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China does not disclose the total number of nuclear-capable (including dual-capable) delivery vehicles it possesses.
Last updated: 22 April 2026 18:42
The DPRK does not disclose the total number of nuclear-capable delivery vehicles it possesses. However, state media (KCNA) reveals certain information about delivery vehicles when reporting on missile tests or the unveiling of new weapons systems.
At a ceremony in August 2024, for example, Kim Jung-Un handed over 250 ‘new-type tactical ballistic missile launchers’ to the ‘frontier military units.’[1]
Last updated: 2 May 2026 05:54
Since 2015, France has declared that it possesses three sets of sixteen M51 submarine-launched ballistic missiles (SLBMs), for a total of 48 missiles for deployment on four ballistic missile submarines, and 54 nuclear-armed, air-launched cruise missiles (ASMPA) that can be carried by two squadrons of Rafale aircraft or one squadron of Rafale marine aircraft.
President François Hollande made this announcement in his 2015 speech dedicated to French nuclear deterrence.[1] This information was last repeated in France’s National Report to the Preparatory Committee of the Nuclear Non-Proliferation Treaty (NPT) in 2025.[2] It was not included in the speech of President Emmanuel Macron in March 2026.[3]
Historically, the 1972 Livre Blanc was the first document to give information about the number of ballistic missiles and nuclear squadrons in service. Specifically, it indicated that at the time, France was operating nine airborne nuclear squadrons of Mirage IV, two ground-launched ballistic missile squadrons deployed at Plateau d’Albion, and one nuclear ballistic missile submarine (SSBN), with three others planned to enter service by 1980.[4]
President Mitterrand gave more precise information in his speech of 1994.[5] On that occasion, the French president indicated that the French forces were composed of five SSBNs, each equipped with 16 ballistic missiles able to carry six nuclear warheads. He explained that to accommodate the rotation of the SSBNs, the ballistic missile stockpile was composed of 64 M4 ballistic missiles.
Regarding the French strategic air forces at the time, these were composed of eighteen Mirage IV aircraft and an unspecified number of Mirage 2000 N and Super Étendards, equipped respectively with 15 and 45 air-ground missiles. Up until that date, France still possessed ground-based nuclear forces; President Mitterrand indicated in his speech that eighteen S3 missiles were deployed at the Plateau d’Albion at the time.
Last updated: 22 April 2026 18:42
The Indian government does not disclose a comprehensive list of all its nuclear-capable (and dual-capable) delivery vehicles. It does, however, periodically announce the testing or commissioning of new delivery systems.
For example, in November 2018, the Indian government announced the completion of a ‘triad’ of nuclear delivery systems with the commissioning of the INS Arihant, an indigenously-built, nuclear-powered submarine armed with nuclear-capable ballistic missiles.[1] And in April 2026, the government publicly announced that induction of the INS Aridaman to the Indian Navy, the third of three Arihant-class submarines.[2] Also in 2026, India announced the successful test firing of the Agni-3, an intermediate-range, nuclear-capable ballistic missile with a range of more than 3000 km.[3]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan has never disclosed the total number of nuclear-capable (including dual-capable) delivery vehicles it possesses.
Last updated: 22 April 2026 18:42
Russia does not publicly disclose the total number of nuclear-capable delivery vehicles it possesses.
Under the now-expired New START agreement signed in 2010, Russia provided data to the United States on the number of deployed intercontinental and submarine-launched ballistic missiles and deployed and non-deployed launchers and heavy bombers, until Russia suspended its participation in the agreement in February 2023. New START had bilateral verification provisions but was not subject to verification by any third party.[1][5] Aggregate figures derived from data exchanges under New START were published twice a year by the Russian Ministry of Foreign Affairs. The latest disclosure provides data as of 1 September 2022.[3]
Russian President Vladimir Putin emphasised the value of transparency provided by New START, stating that it ‘played a role in maintaining balance and predictability in the sphere of strategic offensive weapons’.[4] Russia suspended its participation in the Treaty citing what it described as US policies aimed at undermining Russia’s national security. In doing so, Russia also pointed to Ukrainian attacks on several facilities covered by the Treaty, accusing the United States of assisting these attacks while simultaneously seeking inspection access to them.[5]
As a ‘nuclear-weapon state’ under the Nuclear Non-Proliferation Treaty (NPT), Russia has submitted national reports on its implementation of the Treaty at each review conference since 2005. These reports provide limited information on historic reductions in Russian strategic and non-strategic delivery vehicles under previous arms control treaties with the United States.[2]
Last updated: 22 April 2026 18:43
The UK government does not disclose its total number of nuclear-capable delivery vehicles, which consist solely of the Trident II (D5) submarine-launched ballistic missile (SLBM), deployed on the UK’s fleet of four Vanguard-class, nuclear-capable ballistic missile submarines (SSBNs).
The 2021 Integrated Review stated that the government intended to extend its ‘long-standing policy of deliberate ambiguity and no longer give public figures for our operational stockpile, deployed warhead or deployed missile numbers.’[8] Shortly thereafter, the government stated that the United Kingdom ‘has sufficient Trident II D5 missiles for its needs’.[9]
The 2025 Strategic Defence Review and the 2025 National Security Strategy provided no details on missile numbers or deployments.
The United Kingdom originally purchased title to 65 Trident SLBMs from the US under the 1963 Polaris Sales Agreement, amended for procurement of Trident in 1982.[1][10] This was reduced to 58 in 1998.[2] The missiles are designed, produced, stored, and maintained in the United States when they are not deployed on the UK’s fleet of four Vanguard-class SSBNs. The United Kingdom pays an annual contribution to the United States to support ongoing maintenance of the missile stock.[3]
Some UK missiles have been used in live test fires - eleven as of January 2017.[4] Each Vanguard submarine underwent a Demonstration and Shakedown Operation (DASO) upon commissioning, culminating in a live test fire of an unarmed Trident missile at the US missile test range at Port Canaveral, Florida. The process is repeated after each submarine is recommissioned into operational service following a multi-year mid-life overhaul and refuelling.
In 2010 the government’s Strategic Defence and Security Review stated it was reducing ‘the number of operational missiles on the Vanguard-class submarines to no more than eight’ but gave no further details.[5] This statement was repeated in the 2015 Strategic Defence and Security Review.[6]
Last updated: 22 April 2026 18:43
Until March 2023, the United States disclosed its inventory of intercontinental ballistic missile launchers, submarine-launched ballistic missile launchers, and heavy bombers according to the counting rules of the New START Treaty twice a year.[9] These figures were published in aggregated form on the US Department of State website, and the disaggregated data was available upon request.[1]
However, New START counting rules did not necessarily correspond to the actual numbers of delivery systems, as the United States maintains certain test assets that were not subject to counting under the Treaty, and the Treaty also does not cover nuclear-capable fighter-bomber aircraft like the F-15, F-16, and F-35. In addition, because New START focused on counting warheads and launchers, these figures did not include the total numbers of US delivery systems.
The United States typically discloses how many units of new nuclear-capable delivery systems it intends to purchase. For example, disclosures from the US Air Force related to its incoming B-21 Raider heavy bomber indicate that the US government will purchase a 'minimum of 100 aircraft.'[3][4] US officials also occasionally state the number of delivery vehicles of particular types that are present in the US arsenal. In March 2025, the Commander of US Strategic Command advocated to purchase 145 B-21 bombers instead of 100, which 'gives us 220 bombers when the [B-52s] are included.'[5]
Another disclosure related to the acquisition of a new delivery system was the Milestone B procurement decision for the new Sentinel intercontinental ballistic missile (ICBM), acquired through a Freedom of Information Act request. It noted that the United States planned to purchase 659 units of the Sentinel.[2] It is not common practice for the United States to disclose the number of missiles remaining in its inventory as these units eventually get depleted through regular flight tests and maintenance. However, given that missile tests are publicly announced, it is theoretically possible for analysts to keep track of these numbers.
Budget documents and reports from government agencies like the Government Accountability Office, Congressional Budget Office, and Congressional Research Service, also provide data on nuclear-capable delivery systems.[6][7][8]
Last updated: 22 April 2026 18:43
China does not make any formal disclosure regarding the types of nuclear-capable delivery vehicles it possesses. However, sites such the flagship online portal of the Central Military Commission of the Chinese Communist Party, www.81.cn / 中国军网, occasionally comment on the systems China has developed and deployed, as was the case during the Victory Day Parade on 3 September 2025.
Such references usually showcase advancement in China’s military modernization, including nuclear weapons, which the Chinese leadership emphasizes as China’s strategic deterrence force.[1][2][3][4][5][6] [Editor’s note: Some sources cited here are not strictly official government sources but are believed to present information approved for release by the leadership of the Chinese Communist Party.]
Last updated: 22 April 2026 18:42
Overall, the DPRK discloses very limited information on its nuclear-capable delivery systems, usually on occasions such as missile test launches, visits by the country’s Supreme Leader Kim Jong Un to key military facilities, and major national events.
In 2013, DPRK state media (KCNA) reported that the country had conducted its third nuclear test with a ‘smaller, lighter atomic bomb’ and emphasized the importance of developing ‘more precise and miniaturized nuclear weapons and their delivery systems.’[1][2]
KCNA reported in March 2016 that the ‘nuclear warheads have been standardized to be suitable for ballistic missiles by miniaturizing them’ and ‘with a Korean-style structure of mixed charge.’[5]
In 2021, Kim Jong Un stated the intention to ‘make the existing nuclear weapons tactical ones.’[3] During the 2025 military parade marking the 80th anniversary of the founding of the Worker’s Party of Korea, the Hwasongpho-20 intercontinental ballistic missile (ICBM) was presented as ‘the most powerful nuclear strategic weapon system.’[4]
Last updated: 2 May 2026 05:54
Since the White Book on Defense of 1972, France has been open about the various components of its nuclear arsenal, and in particular, has indicated which types of delivery vehicles it possesses and operates.[1]
Official documents and speeches have confirmed that France currently operates intercontinental submarine-launched ballistic missiles (SLBMs) carried by its nuclear-powered submarines, and air-launched cruise missiles carried by its Rafale aircraft.[2][3] The ballistic missile submarines are dedicated only to the nuclear mission, whereas the Rafale aircraft can be tasked with carrying the nuclear ASMPA cruise missiles, or tasked with other conventional missions.[2] The range of the SLBM is declared to be around 10,000 km.[2]
Historically, France also possessed nuclear-armed ground-launched ballistic missiles of various types, and nuclear-armed gravity bombs, but those have been dismantled as announced in various documents.[4]
Last updated: 22 April 2026 18:42
India occasionally discloses different types of nuclear-capable, including dual-capable, delivery systems it possesses. This information is often disclosed as part of any actual or planned advancements in the modernisation of the arsenal, including test launches.
In November 2018, the Prime Minister’s office announced the completion of a ‘triad’ of nuclear delivery systems with the commissioning of the INS Arihant, an indigenously built, nuclear-powered submarine armed with nuclear-capable ballistic missiles.[12] In 2024, the Defense Minister gave public remarks at the commissioning ceremony of the INS Arighaat, the second Arihant-class submarine.[5] And the Indian government invited journalists to report on the development and induction of the third Arihant-class submarine, INS Aridaman, which was inducted in 2026.[10][11]
Some official Indian statements do not mention the nuclear capabilities of specific delivery systems explicitly but signal their role in Indian nuclear deterrence indirectly. For example, the 2025 announcement by the Ministry of Defence of the successful test launch of the Pralay missile mentioned that it can carry ‘multiple’ types of warheads.[1] Similarly, the 2022 statement from the Ministry of Defence announcing the successful test launch of the short-range Prithvi II missile did not mention its dual-use nature,[2] but the 2023 announcement of another successful Prithvi II test launch stated that it is an integral part of ‘India’s nuclear deterrent’.[3]
In 2025, the Ministry of Defence announced that the Strategic Forces Command, which is responsible for India’s nuclear arsenal, had successfully test launched a Prithvi II and Agni I, another short-range missile, emphasising that ‘these tests validate key capabilities of India’s nuclear-capable delivery systems.’[4]
Since 2016, India has also publicly announced multiple successful test launches of the Agni V missile, which is a long-range, surface-to-surface missile capable of delivering Multiple Independently Targetable Re-Entry Vehicles (MIRVs) and has explicitly been characterised as nuclear-capable.[6][7][8]. In 2021, India announced the test launch of the Agni P ballistic missile, which is also nuclear-capable.[9]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan has disclosed all the different types of nuclear-capable delivery vehicles it possesses, including some that are dual-capable (nuclear/conventional). Lt. Gen. (Retd) Khalid Kidwai, an advisor to the National Command Authority of Pakistan, has stated that the country ‘possesses the full spectrum of nuclear weapons in three categories: strategic, operational and tactical, with full range coverage of the large Indian land mass and its outlying territories.’[9]
Official media outlets of the Pakistani government, including the media agency of the Pakistani military, the Inter Services Press Relations (ISPR), regularly post announcements of tests and drills related to nuclear-capable delivery systems.[10] These provide varying details about the name, role, range, and capabilities of Pakistani nuclear delivery systems, including ballistic missiles, ground and air-launched cruise missiles, and maritime nuclear capabilities.
An indicative – but not exhaustive – sample of the types of information published includes details about the following Pakistani nuclear-capable delivery systems:
A ground-launched, dual-capable cruise missile, the Babur, was initially announced in 2011.[1] The ISPR then announced in 2016 that the range of the Babur system had been upgraded to 700km,[2] and in 2017, announced the successful test-launch of a submarine-launched version of the missile with a range of 450km.[3]
In 2011, the ISPR announced a successful test of the dual-capable air-launched cruise missile, the Ra’ad.[4] In 2020, the ISPR announced the successful first flight of the Ra’ad-II, which they stated had a longer range of 600km.[5]
The ISPR also made announcements related to the development of short-range ballistic missiles: the 60-70km-range Nasr in 2017, [6] and an operational training launch of the 290km-range Ghaznavi in 2020. [7]
The existence of longer-range ballistic missile systems has also been announced, including a successful test-launch of the 2,750km-range Shaheen-III in 2021, among others. [8]
Last updated: 22 April 2026 18:42
Russia does not disclose all the different types of nuclear-capable delivery vehicles it possesses.
Under the 2010 New START Treaty, Russia provided the United States with data on types of deployed and non-deployed strategic missiles and their launchers as well as heavy bombers, until suspending its participation in the Treaty in February 2023. New START had bilateral verification provisions but was not subject to verification by any third party.[1] Aggregate figures derived from data exchanges under New START were published twice a year by the Russian Ministry of Foreign Affairs. The latest disclosure provides data as of 1 September 2022.[4]
Russian President Vladimir Putin emphasised the value of transparency provided by New START, stating that it ‘played a role in maintaining balance and predictability in the sphere of strategic offensive weapons’.[5] Russia suspended its participation in the Treaty citing what it described as US policies aimed at undermining Russia’s national security. In doing so, Russia also pointed to Ukrainian attacks on several facilities covered by the Treaty, accusing the United States of assisting these attacks while simultaneously seeking inspection access.[6]
Information about certain types of nuclear-capable systems is occasionally disclosed through official statements and government press releases. For example, in 2024 Russia used a new type of dual-capable (nuclear and conventional) intermediate range ballistic missile in Ukraine; after the missile was used the Russian President made public statements describing the missile and its capabilities.[2][3]
Last updated: 22 April 2026 18:43
The UK government has disclosed that the country has one nuclear weapons delivery system, comprising US Trident II (D5) Submarine-Launched Ballistic Missiles (SLBMs) deployed across a fleet of four UK Vanguard-class, nuclear-capable ballistic missile submarines (SSBNs). The UK government has publicly stated that the Vanguard-class SSBNs will be replaced in the 2030s with four Dreadnought-class SSBNs currently under construction.[1][5]
The UK government has also publicly disclosed that it participated in the US programme to upgrade the Trident II (D5) SLBMs to the D5LE (Life Extension) version([2]. The US has now embarked on a second life extension programme (D5LE2) to extend the life of the missile to the 2080s.[3]
The United Kingdom’s last air-launched nuclear weapons (WE177 gravity bombs) were withdrawn from service in 1997.[4] The United Kingdom does not currently deploy any other types of nuclear weapons or any other nuclear delivery vehicles. On the planned acquisition of F-35A nuclear capable jets, see the data on ‘modernisation plans’.
Last updated: 22 April 2026 18:43
The annual Stockpile Stewardship and Management Plan of the US National Nuclear Security Administration (NNSA) includes a table of all current warheads in the US stockpile and their associated delivery systems, although it is primarily intended to describe plans for warhead modernization, infrastructure recapitalization, and workforce development. The table lists every delivery system capable of carrying each particular warhead; the mission of each warhead, distinguishing between strategic and nonstrategic weapons; and which service (Air Force, Navy, or select NATO forces) is responsible for its deployment.
In the Stockpile Stewardship and Management Plan for Fiscal Year 2025, the United States includes the following categories of nuclear-capable delivery systems: Minuteman III intercontinental ballistic missile(ICBM); Trident II D5 submarine-launched ballistic missile; F-15; F-16; F-35; certified NATO aircraft; B-2 bomber; and B-52 bomber.[1]
Similar information can be found in reports from other sources like the Government Accountability Office (GAO). For example, a 2021 GAO publication included a table of all currently fielded and replacement nuclear triad delivery systems, missiles, and nuclear weapons. It included the same systems as listed in the Stockpile Stewardship and Management Plan, as well as the following replacement delivery systems: Columbia-class ballistic missile submarine, Long Range Standoff missile (LRSO), B-21 bomber, and Ground Based Strategic Deterrent ICBM.[2]
Last updated: 22 April 2026 18:43
China does not disclose information about its fissile material production or reprocessing facilities used for nuclear weapons purposes.
Last updated: 22 April 2026 18:42
The DPRK discloses little information about the types of fissile material production or reprocessing facilities it possesses that are used for nuclear weapons purposes.
Sites disclosed by the DPRK include Nyongbyon and a facility that was under construction in Taechon at one point, as referenced in the 1994 Agreed Framework signed between the DPRK and the United States.[1][2][3][6] In April 2009, in response to a statement from the president of the UN Security Council, the DPRK Foreign Ministry also stated an intention to build an experimental light-water reactor: ‘In case the UNSC does not make an immediate apology, we will…decide to build a light-water reactor power plant and begin immediately the technological development to ensure our own production of nuclear fuel.’[7]
The Ministry of Foreign Affairs first publicly acknowledged the possession of a uranium enrichment capability in June 2009, when government media reported that in response to UNSC Resolution 1874, ‘The process of uranium enrichment will be commenced.’[9]
Official state media (KCNA) also occasionally mentions the names of facilities that produce fissile materials for nuclear weapons purposes, such as the Nuclear Weapons Institute.[8] In 2025, it reported on Kim Jong Un’s interactions with scientists from the nuclear-material production base and the Nuclear Weapons Institute and posted photos of him inspecting the related facilities, though the DPRK has not disclosed their locations or technical parameters.[4][5]
Last updated: 2 May 2026 05:54
France announced in 1996 that it had stopped the production of fissile material for nuclear weapons and had started the dismantlement of its production facilities (Pierrelatte and Marcoule). As such, there are no longer any operational facilities producing fissile material for nuclear weapons in France.
France stopped the production of plutonium for nuclear weapons in 1992 and of highly enriched uranium for this purpose in 1996. President Chirac announced during a TV interview that the Pierrelatte facility would close on 22 February 1996.[1] The decommissioning of the Pierrelatte enrichment plant started in 1997 and will continue until 2040. The dismantlement of the G1, G2 and G3 plutonium-producing reactors at Marcoule has been completed.[2] France has organised several visits for international observers to the former production sites.[3]
Last updated: 22 April 2026 18:42
India does not publicly disclose the types of fissile material enrichment or reprocessing facilities it possesses that are used for nuclear weapons purposes. There has never been an explicit government statement linking its specific reactors to production of weapons-grade fissile material. However, under the Agreement on the Prohibition of Attack against Nuclear Installations and Facilities between India and Pakistan, which was signed in 1988 and entered into force in 1991, there is a mutual exchange of information on an annual basis, in which the two countries exchange details on the location of sensitive sites such as fuel fabrication, enrichment and reprocessing facilities.[2]
India publicly acknowledges its reprocessing activities of Spent Nuclear Fuel to extract plutonium and uranium, meant exclusively for the purposes of re-using the nuclear materials for its three-stage, closed-fuel cycle nuclear energy programme.[1] Major reprocessing facilities are housed at Tarapur and Kalapakkam sites in Maharashtra and Tamil Nadu states respectively.[1]
India’s enrichment and fissile material production activities are undertaken at sites that are outside the remit of the IAEA safeguards and hence, no public information is available on these sites, except that they are used for basic research, training and production of isotopes.[3]
India’s enrichment facilities that generate fuel for its nuclear-powered and nuclear-armed submarines include the Rare Materials Project in Rattehali, Karnataka state, which is the main centrifuge facility, as revealed in a discussion with Dr Srikumar Banerjee, then Chairman of Atomic Energy Commission of India.[3]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan has not publicly disclosed any information about the fissile material production or reprocessing facilities it possesses that are used for nuclear weapons purposes. However, Pakistan and India engage in a mutual exchange of data about their nuclear facilities once a year, under a 1988 ‘Non-Attack Agreement’ that commits both parties not to attack the nuclear facilities of the other. [1]
The Agreement, which entered into force in 1991, commits the two parties to ‘refrain from undertaking, encouraging or participating in, directly or indirectly, any action aimed at causing the destruction of, or damage to, any nuclear installation or facility in the other country.’ To facilitate this, each party commits to inform the other on 1 January each year of ‘the latitude and longitude of its nuclear installations and facilities and whenever there is any change.’ As defined in the Agreement, this includes ‘nuclear power and research reactors, fuel fabrication, uranium enrichment, iso-topes separation and reprocessing facilities as well as any other installations with fresh or irradiated nuclear fuel and materials in any form and establishments storing significant quantities of radio-active materials.’[1] The annual exchange of facilities lists has been maintained since 1 January 1992.[2]
Last updated: 22 April 2026 18:42
Russia has disclosed information about the types of fissile material production and reprocessing facilities it possesses that were previously used for nuclear weapons purposes.
Soviet leader Mikhail Gorbachev announced in 1989, during a visit to the United Kingdom, that the Soviet Union would cease production of uranium for weapons purposes by the end of the year.[1][2] At the 1995 Review Conference of the Nuclear Non-Proliferation Treaty (NPT), Russia declared that it had stopped using newly-produced plutonium for weapons purposes and that a programme was under way to shut down the remaining facilities which had previously produced plutonium for weapons purposes.[3] In 2010, then-Russian President Dmitry Medvedev announced that the last reactor producing weapons-grade plutonium would be shut down by the end of the year.[4] Russia announced that the last reactor had been halted in its national report to the 2010 NPT Review Conference.[5]
Lists of highly enriched uranium (HEU) production sites and plutonium production sites and reactors have also been publicly disclosed to the United States in mutual data exchanges under the following bilateral treaties:
— 1993 Agreement Concerning the Disposition of Highly Enriched Uranium Extracted from Nuclear Weapons,[6]
— 1994 Agreement Concerning the Shutdown of Plutonium Production Reactors and The Cessation of Use of Newly Produced Plutonium for Nuclear Weapons,[7]
— 1997 Agreement Concerning Cooperation Regarding Plutonium Production Reactors.[8]
Last updated: 22 April 2026 18:43
The United Kingdom no longer operates any fissile material production or reprocessing facilities for nuclear weapons purposes. The government announced in April 1995 that it ‘had ceased the production of fissile material for explosive purposes.'[1]
Production of HEU for defence programmes at the Capenhurst Plant in the United Kingdom ended in 1962. Since then, the country has received HEU for both its warhead programme and naval reactor programme through exchanges of special nuclear material with the US Department of Energy under the 1958 Mutual Defence Agreement. In the 1960s, the Capenhurst plant was modified to produce low-enriched uranium (LEU) for civil nuclear power reactors until it ceased operations in 1982.[2]
The UK has operated three reprocessing facilities at its Sellafield nuclear site: the First Generation Reprocessing Plant (B204), operating from 1952 to 1964, extracted plutonium from spent nuclear fuel for the UK nuclear weapon programme. It was replaced by the Magnox Reprocessing Plant (B205), which operated from 1964 to 2022. The Magnox Reprocessing Plant reprocessed spent fuel from UK Magnox nuclear reactors for civilian purposes until 2022 and for military purposes until 1995. It is now in cleanup/decommissioning. The Thermal Oxide Reprocessing Plant (THORP) was a civil reprocessing plant that operated from 1994-2018 but did not separate plutonium for the UK nuclear weapons programme.[3]
The Calder Hall Magnox power station at the Sellafield site, consisting of four dual-purpose reactors, began operations in 1956 for commercial electricity generation and plutonium production for defence needs. The Chapelcross power station in Southern Scotland operated on the same basis as Calder Hall from 1958.
Following the UK government’s announcement in 1995 that it would end production of fissile material for the nuclear weapons programme, the Calder Hall reactors were brought under Euratom safeguards and made liable to inspection under the terms of the safeguards agreement between the United Kingdom, Euratom and the IAEA.[1] Calder Hall closed in 2003.
Chapelcross reactors continued to produce tritium for nuclear weapons and were not subject to international safeguards inspection. However, the 1998 Strategic Defence Review announced that all reprocessing of spent fuel from defence reactors at Chapelcross would in future be conducted under Euratom safeguards and made liable to inspection by IAEA.[4] Chapelcross ceased operations in 2004.
Last updated: 22 April 2026 18:43
In 2020, the US Department of Defense published an updated version of its Nuclear Matters Handbook, which gives a comprehensive overview of the US nuclear arsenal. The latest edition includes a detailed examination of the National Nuclear Security Administration’s Nuclear Security Enterprise, spanning eight sites: Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Sandia National Laboratories, Kansas City National Security Campus, the Pantex Plant, the Savannah River Site, the Y-12 National Security Complex, and the Nevada National Security Site.[1]
The Nuclear Matters Handbook also includes details about the 'strategic materials' that are managed at each site, and their relation to the nuclear arsenal: the Los Alamos National Laboratory is currently responsible for managing plutonium pits–the core of a nuclear weapon that initiates the chain reaction required for a nuclear explosion; the Y-12 complex is responsible for managing uranium and lithium; and the Savannah River Site is responsible for managing tritium.
The Handbook also notes plans for the conversion of the Mixed Oxide Fuel Fabrication Facility at the Savannah River Site to a plutonium processing facility that will be capable of producing at least 50 pits per year, and for the recapitalization of a plutonium facility at Los Alamos National Laboratory to produce at least 30 pits per year. It further notes that the US government currently has no capacity to enrich uranium domestically but is developing plans to re-establish that capability.[1]
Last updated: 22 April 2026 18:43
China does not disclose its total holdings of low-enriched uranium, highly-enriched uranium, or plutonium.
Last updated: 22 April 2026 18:42
The DPRK does not disclose its total holdings of low-enriched uranium, highly enriched uranium, or plutonium.
Last updated: 2 May 2026 05:54
France does not disclose its total holdings of low-enriched uranium, highly enriched uranium, or plutonium. However, it has transparently dismantled the facilities that it formerly used to produce fissile material for nuclear weapons (in Pierrelatte and Marcoule).
France has not explained its decision not to communicate on its holdings of fissile material. At the Review Conference of the Nuclear Non-Proliferation Treaty in 2000, it stated that it does not have any weapon-grade fissile material in excess of its military requirements.[2] France has stated on many occasions that it stopped the production of fissile material for nuclear weapons in 1992 (plutonium) and 1996 (highly enriched uranium). France dismantled its fissile material production factories in an irreversible manner in the 2000s.[1]
Last updated: 22 April 2026 18:42
The Indian government does not disclose its total holdings of low-enriched or highly enriched uranium (LEU / HEU) or plutonium.
As far as natural reserves are concerned, India possesses approximately 428,300 tonnes of in-situ uranium oxide, spread across 47 uranium deposits.[1] In addition, India plans to import 9,000 MTU (metric tonne units) of natural uranium in the period 2025 to 2033, as confirmed by a government official.[2] While the LEU requirement for some specific, foreign-built reactors such as the Tarapur Atomic Power Station 1&2 and the Kudankulum Nuclear Power Project Unit 1&2 is estimated at 40 tonnes and 150 tonnes respectively, India’s own indigenous Pressurised Heavy Water Reactors do not require LEU.[3] Additionally, the Indian government has phased out the use of HEU in reactors to prevent its misuse.[4]
India follows a strict policy of ‘reprocess to reuse’ where any spent fuel from the safeguarded nuclear reactors is fed back into the fast breeder reactors to prevent any build-up (stockpiling) of plutonium.[4]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan has not disclosed its total holdings of low-enriched uranium, highly-enriched uranium, or plutonium, nor has it disclosed its production capacities in regard to these materials.
Last updated: 22 April 2026 18:42
Russia does not disclose its total holdings of low-enriched uranium, highly enriched uranium, or plutonium. As a ‘nuclear-weapon state’ as defined in the Nuclear Non-Proliferation Treaty (NPT), Russia has a ‘voluntary offer agreement’ with the International Atomic Energy Agency (IAEA) under which it can designate certain civilian fissile material to be placed under IAEA safeguards. Any fissile material that is not designated under the voluntary offer agreement remains exempt from IAEA safeguards.[3]
Russia only publicly discloses information about its civilian stock of plutonium, which is done under the Guidelines for the Management of Plutonium (INFCIRC/549) published by the IAEA. These annual reports to the IAEA by the Russian State Nuclear Company (ROSATOM) include information on Russian holdings of civil unirradiated plutonium and the estimated amounts of plutonium contained in spent (i.e. irradiated) civil reactor fuel.[1]
Limited information about historical fissile material disposition programmes is made public through Russia’s national reports on its implementation of the NPT, submitted to NPT Review Conferences since 2005. These reports do not include quantitative data on current fissile material stocks but mention the amount of weapons-grade HEU down-blended into LEU under the Russia-US HEU-LEU Agreement.[2][4]
Last updated: 22 April 2026 18:43
The United Kingdom partially discloses its holdings of low-enriched uranium, highly-enriched uranium (HEU), and plutonium. The country stopped production of fissile material ‘for explosive purposes’ in April 1995.[1] In 2000, it published a historical accounting of its plutonium production for defence purposes up to 1999.[1] And in 2006, it published a historical accounting of its HEU production for defence purposes up to 2002.[2] It has not subsequently updated these reports.
The United Kingdom reports to the International Atomic Energy Agency (IAEA) under three frameworks: a Voluntary Offer Safeguards Agreement (VOA);[4] an Additional Protocol;[5] and voluntary transparency commitments. The United Kingdom also publishes annual disclosures of nuclear material withdrawn from safeguards and the reasons why.[7]
Under its VOA, the United Kingdom provides two annual reports to the IAEA. First, a Material Balance Report of holdings of civil HEU and civil depleted, natural, and low-enriched uranium. And second, a Physical Inventory Listing, which catalogues all nuclear materials present at each nuclear facility at the time. The United Kingdom also reports regularly on changes in civil fissile material holdings, typically monthly.[4]
Under the UK-IAEA Additional Protocol,[5] the UK government reports, usually annually or in event-based declarations, on nuclear fuel-cycle R&D, uranium mining and milling, nuclear-related manufacturing, exports/imports of sensitive equipment, and site-level information on nuclear locations. It also grants IAEA inspectors complementary access to fuel-cycle facilities and locations.
As a voluntary measure under IAEA Guidelines for the Management of Plutonium (INFCIRC/549), the United Kingdom reports annual declarations of its civilian plutonium.[3] These voluntary guidelines were established in 1998, and participating states publish annual, public figures for civil unirradiated plutonium (plus an estimate for plutonium in spent fuel). Some states, including the United Kingdom, choose to add civil HEU figures for greater transparency.
In 2010, the United Kingdom reiterated that it was under no obligation to report the production, transfer, or use of fissile material for defence purposes to the IAEA because such material is outside the international safeguards regime.[8] It is subject, however, to a strict internal materials accountancy regime.[6]
Last updated: 22 April 2026 18:43
The United States displays different levels of transparency regarding its total holdings of fissile materials, depending on the type of material.
In 1998, the International Atomic Energy Agency (IAEA) published Guidelines for the Management of Plutonium (INFCIRC/549), for which the five countries defined as ‘nuclear weapon states’ in the Nuclear Non-Proliferation Treaty (NPT) agreed to publish annual statements of their holdings of civil plutonium. While INFCIRC/549 covers most categories of plutonium, certain categories—such as plutonium with an isotopic concentration of plutonium-238 exceeding 80 percent, plutonium on which IAEA safeguards have been exempted or terminated, or plutonium used in gram quantities or as a sensing component in instruments—are exempt.[1]
The most recent US declaration, from 2023, noted holdings of less than 0.05 metric tons of unirradiated separated plutonium produced during the course of manufacture or fabrication, 4.6 metric tons of plutonium contained in unirradiated MOX fuel, and 44.6 metric tons of unirradiated separated plutonium held elsewhere—all of which were roughly the same as the previous year’s figures.[2]
INFCIRC/549 does not cover holdings of low-enriched or highly-enriched uranium (HEU), and the United States does not regularly provide any public information on these stocks. The most recent US disclosure regarding its HEU stocks was in a 2016 Fact Sheet published by the White House, which included data from between 1996 and 2013.[3] The Fact Sheet noted that as of September 30, 2013, the total US inventory of HEU was 585.6 metric tons, of which 499.4 metric tons was for 'national security or non-national security programs including naval propulsion, nuclear energy, and science.'
The Fact Sheet also noted that 'of the remaining 86.2 metric tons, 41.6 metric tons was available for potential down-blend to low enriched uranium or, if not possible, disposal as low-level waste, and 44.6 metric tons was in spent reactor fuel.'[3]
Last updated: 22 April 2026 18:43
While China recognizes the potential benefits of AI in military applications, it has also repeatedly emphasized the imperative of maintaining human control in nuclear decisionmaking, and has highlighted the potential risks involved in AI integration in military affairs.[5] It has noted, for example, that AI is contributing to a reshaping of ‘the traditional strategic offense-defense dynamic, posing new challenges to global strategic stability.’[4]
In a position paper submitted to the United Nations in April 2025, China does not mention nuclear weapons specifically, but states, ‘a people-centered approach should be upheld. It is essential to always regard human as the final subject of responsibility and ensure that relevant weapon systems must be under human control’.[3]
In its submission to the First Committee (Disarmament and International Security) of the UN General Assembly in October 2025, the Chinese delegation stated: ‘China attaches great importance to the huge risks posed by the use of Artificial Intelligence in military domain, and advocates that countries should excise [sic] restraint in developing Artificial intelligence weapon system, ensuring the use of AI in military domain in compliance with international humanitarian law, and preventing the indiscriminate killing and injuring and malicious use of those weapon systems’.[1]
At a press conference in March 2026, PRC Ministry of National Defence spokesperson, Senior Colonel Jiang Bin pointed out, ‘Upholding a people-centered approach and the principle of AI for good, China believes that human primacy must be upheld in military applications of AI, and that all relevant weapon systems must be put under human control’.[2]
Last updated: 22 April 2026 18:42
The DPRK does not publicly disclose its policies regarding the integration of AI into its nuclear weapons systems. However, the country’s Supreme Leader, Kim Jong Un, has stated that the integration of AI technologies is a top priority for its military modernization.[1]
For example, during a visit to the Unmanned Aeronautical Technology Complex and the detective electronic warfare research group in March 2025, Kim stated that ‘in the effort to modernize the armed forces, the sectors of unmanned equipment and AI technology must be regarded as top priorities for development’.[1]
And at the opening ceremony of the Arms Equipment Exhibition in October 2025, Kim stressed the importance of ‘actively introducing AI and other cutting-edge technology which could not only expand our warfighting capabilities but also our adaptability to current and future battlefields.’[2]
Last updated: 2 May 2026 05:54
France has not made a full statement regarding the use of artificial intelligence (AI) in the development, deployment, and employment of French nuclear weapons, but has indicated that it refused to ‘entrust the decision of life or death to a machine that would act fully autonomously and escape any form of human control’.[1]
Regarding the use of AI in defense matters generally, French Defense Minister Florence Parly indicated in 2019 that the development of new technologies by France would be pursued on the basis of three principles: ‘abiding by international law, maintaining a sufficient human control, and ensuring the permanent responsibility of the chain of command.’[1]
In 2022, France supported a joint statement with the United Kingdom and United States according to which the three states ‘will maintain human control and involvement for all actions critical to informing and executing sovereign decisions concerning nuclear weapons employment’.[2]
Last updated: 22 April 2026 18:42
The Indian government does not clearly disclose whether it uses artificial intelligence in systems related to nuclear weapons development, deployment, and use. More broadly, however, it has made clear that ‘In the military domain, India is committed to its responsible use of AI’.[1] In the nuclear weapons sphere, India has emphasised that ‘the use of AI in the nuclear command and control raises questions’,[1] and that any such advancement will include a ‘human-in-the-loop’ approach, as emphasised by Deputy Chief of Army Staff, Lieutenant General Vipul Shinghal.[2]
However, there is no confirmation as to whether India is moving towards integrating AI systems into its nuclear command and control. For now, India’s use of AI in defence remains limited to Electronic Warfare analytics, drone swarms, surveillance and cyber defence.[3][4][5] India has deployed AI in the procurement and financial management of all defence purchases, which may include dual-use delivery systems.[6]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan has not disclosed its operational policies and practices regarding the use of AI in systems related to nuclear weapons. However, Pakistan does not support the use of AI in nuclear decision making processes as it could undermine the rationale of deterrence that rests on human factors alone.
In a working paper submitted to the Conference on Disarmament in 2023, Pakistan stated: ‘The development, deployment, integration and use of AI for military purposes, as well as autonomous weapon systems entail serious repercussions for security and stability at the international and regional levels. These capabilities, when developed and employed without any guardrails, can exacerbate nuclear risks. And when these capabilities are integrated with policies relating to nuclear force posture as well as employment, they can lead to miscalculations, accidents and thereby catastrophic consequences. Concepts of deterrence escalation and risk reduction heavily rely on human rationality, caution, perception and management of the situation politically. Perceived or real absence of human factor renders these concepts without their traditional meaning with risk of automating escalation.’[1]
Last updated: 22 April 2026 18:42
Russia does not disclose its policies or operational practices regarding the use of artificial intelligence in systems related to the development, deployment, and employment of nuclear weapons. However, statements from senior military officials indicate a general view on such integration and potential areas for the application of AI.
For example, the commander of Russian Strategic Rocket Forces (RVSN) Sergey Karakaev stated on 17 December 2021 (designated by Presidential Decree as Strategic Rocket Forces Day) that the use of AI and robotics is being explored for automated security systems of mobile and stationary strategic missile complexes and potentially may be employed for ‘automation of certain routine operations previously performed by duty crews.[1]
Karakayev also stated in 2024 that when it comes to ‘making a decision to use nuclear weapons, replacing a human is currently inappropriate’, as AI technologies being introduced to automate even some routine operations in the RVSN have not yet been ‘fully studied and worked out’.[2]
Further clarification of Russia’s position on the use of AI in the nuclear field was disclosed in its 2026 national report to the Review Conference of the Nuclear Non-Proliferation Treaty. In that document, Russia stated that ‘the decision to use nuclear weapons is taken by the President of the Russian Federation’ and that ‘the Russian Federation ensures decisive human involvement and judgment in the field of nuclear weapons on an ongoing basis, including strict control at the level of the country’s highest military and political leadership. Against the backdrop of technological progress, this approach remains an absolute constant.’[3]
Last updated: 22 April 2026 18:43
There is no official UK government statement, parliamentary record, or defence policy document that describes the application, limits, or governance of artificial intelligence in relation to the UK’s nuclear command, control and communications system (NC3); early-warning or decision-support systems; or the development, targeting, or employment of nuclear weapons.
However, the UK government’s 2022 Defence Artificial Intelligence Strategy stated that the UK ‘must shape global AI developments to promote security, stability and democratic values’ and that ‘We will ensure that – regardless of any use of AI in our strategic systems – human political control of our nuclear weapons is maintained at all times. We strongly encourage other nuclear states to make a similar commitment.’[1] This was reiterated in 2023.[2]
In 2025, the UK government was asked in parliament ‘if artificial intelligence has been used to support (a) routine operations and (b) policy in relation to nuclear capability.' It replied, ‘The delivery of defence capabilities enabled by artificial intelligence (AI) will be ambitious, safe and responsible. Research to identify, understand, and mitigate against risks of applying AI for sensitive defence affairs is underway. Routine nuclear deterrence operations continue to be conducted in accordance with the highest standards and controls. Regardless of any potential application of artificial intelligence in our strategic systems, we will ensure human political control of our nuclear weapons is maintained at all times.'[3]
In December 2023, the UK House of Lords Committee on ‘Artificial Intelligence in Weapon Systems’ published its report, ‘Proceed with Caution’.[4] The report noted that a key element in regulating autonomous weapons systems ‘will be prohibiting the use of AI in nuclear command, control and communications’ (p. [4]. In its response to the report, the UK government added ‘The UK is at the forefront of work internationally to reduce the risk of nuclear conflict and enhance mutual trust and security, and will continue to promote and engage with international dialogue aimed at identifying and addressing crucial AI-related strategic risks.'[5]
Last updated: 22 April 2026 18:43
The US Nuclear Posture Review (NPR), generally issued by each presidential administration, describes US nuclear policy, posture, and force structure, and their interaction with emerging technologies like AI. The most recent iteration of the NPR, published in 2022, states that '[i]n all cases, the United States will maintain a human “in the loop” for all actions critical to informing and executing decisions by the President to initiate and terminate nuclear weapon employment.'[1]
The Commander of US Strategic Command testified to Congress in March 2025 that 'AI will remain subordinate to the authority and accountability vested in humans,' although he did note that the service will use artificial intelligence and machine learning capabilities 'to enable and accelerate human decision-making.'[2] The ultimate decision to use nuclear weapons, however, is one of the few remaining areas relating to US nuclear arsenal where AI does not play an active role.
The Department of Energy’s 'Artificial Intelligence Strategy,' published in October 2025, and the National Nuclear Security Administration’s 'Artificial Intelligence for Nuclear Deterrence Strategy,' published in 2023, both provide details as to how AI is being integrated into the nuclear mission. Of particular note is that AI is increasingly being used to support the stockpile stewardship mission by enhancing US modelling and simulation capabilities, by accelerating and automating the manufacture of systems needed for nuclear deterrence, and by assisting with the maintenance of nuclear weapon systems as they age.[3][4]
The United States does not disclose the ways in which AI is being integrated into its infrastructure for early warning and nuclear command, control, and communications (NC3), but public statements from officials involved in the NC3 modernization process indicate that such integrations are occurring.[2][5]
Last updated: 22 April 2026 18:43
China discloses general and broad rationales for why it believes nuclear modernization is needed but not specific plans for the future development of its nuclear arsenal or fissile material production and related facilities.
In its 2025 white paper on nuclear arms control and disarmament, it states, ‘In building a lean and effective nuclear force system, China is improving its capabilities in strategic early warning, command and control, missile penetration, and rapid response, as well as its survivability, in order to ensure the safety, security, reliability and effectiveness of its nuclear weapons and deter other countries from using or threatening to use nuclear weapons against China’.[5]
Leadership statements and various defence white papers all refer to the changing international security environments as the justification for China to continue its nuclear modernization and the imperative of building the PLA Rocket Force into a reliable, survivable, lean and effective strategic force to deter and counter nuclear coercion or blackmail.[1][2][3][4][5]
Last updated: 22 April 2026 18:42
The DPRK has disclosed plans for the modernisation or future development of its nuclear arsenal and explained the strategic rationale for the proposed changes.
At the 8th Congress of the Workers’ Party of Korea in 2021, Kim Jong Un announced the modernization plan for the next five years to ‘further advance nuclear technology, the miniaturization and lightening of nuclear weapons, the development of tactical nuclear weapons, and the production of ultra-large nuclear warheads.’ This plan also include the ‘goal to improve the preemptive and retaliatory strike of nuclear forces…within the 15,000 km range’ and the ‘task to establish hypersonic glide combat unit in the near future, ground-based and sea-based solid-fuelled intercontinental ballistic missiles, as well as nuclear-powered submarines and underwater-launch nuclear strategic weapons which are of important significance in raising the long-range nuclear strike capability.’[1]
Kim has stressed that the country will pursue ‘a rapid expansion of nuclearization’ and emphasized the important role of naval forces to perform as a part of ‘state nuclear forces and the realm of nuclear use in the near future.’[2]
Last updated: 2 May 2026 05:54
France has regularly disclosed information about the planned modernisation of its nuclear delivery vehicles and the associated nuclear-powered submarines. Public discussion of these programmes is available through parliamentary documentation in particular.
France has announced publicly that since 2017, it has been actively renewing the two components of its nuclear arsenal (oceanic and air-delivered). The strategic oceanic forces will be equipped with a new version of the M51 intercontinental ballistic missile (ICBM), and the construction of a third generation of nuclear-powered ballistic missile submarines has been launched (SNLE 3G). The first SNLE 3G is due to enter service in 2036. In March 2026, President Macron specified that it would be named ‘L’Invincible’.[1]
The airborne nuclear component will be equipped with new hypersonic cruise missiles (ASN4G), including new warheads. This missile is being developed by MBDA and is also due to become operational starting in 2035. It will initially be integrated on the Rafale F5 aircraft, and later, on the Next Generation Fighter (NGF), an aircraft that is planned for production in the framework of the European Future Combat Air System (FCAS) programme.[2]
Budgets and rationales for these programmes have been published by the Parliament, with outputs from programme managers of the Ministry of Armed Forces. The government has stated that this modernisation is necessary to preserve the robustness and credibility of French nuclear deterrence in the changing strategic context and given the rise of new threats.[3]
Last updated: 22 April 2026 18:42
The Indian government occasionally and selectively discloses plans for the modernisation of its nuclear arsenal, such as the commissioning of its nuclear-capable submarine (SSBN) fleet.[1][2] On occasion, these disclosures were made via public statements to news media.[5][6] The Indian government has also consistently released its plans for the advancement in the nuclear-capable Agni missile series.[3][7][8]
Regarding the strategic rationale for India’s development of its nuclear arsenal, in a 1999 interview with the Hindu newspaper, India’s then-Foreign Minister Jaswant Singh clarified that with India’s policy of ‘retaliation only’, a ‘minimum’ deterrent cannot be a fixed quantification; ‘it is a dynamic concept but firmly rooted in the strategic environment, technological imperatives and national security needs, and the actual size, components, deployment and employment of nuclear forces will be decided taking into account all these factors.’[4]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan does not disclose any plans for the modernisation or future development of its nuclear arsenal, including facilities related to the production and storage of nuclear warheads, fissile material for weapons purposes, or nuclear-capable delivery systems.
Last updated: 22 April 2026 18:42
Russia partially discloses its plans for the modernisation and future development of its nuclear arsenal and explains the strategic rationale for proposed changes. However, publicly disclosed information only outlines broad priorities and goals rather than specific dimensions of the modernisation programme. These are mainly disclosed through official statements by senior Russian officials.
The Russian modernisation programme involves the replacement of Soviet-era systems and development of new strategic delivery vehicles. Statements by senior officials broadly describe the overall progress in modernising the nuclear forces, development, deployment, and testing of some of the new delivery vehicles and priorities for further modernisation.
For example, in 2018, Russian President Vladimir Putin announced the development of new nuclear-capable delivery systems, including a new intercontinental ballistic missile (ICBM), ‘RS‑28 Sarmat’; a hypersonic glide vehicle, ‘Avangard’; an air-launched hypersonic missile, ‘Kh‑47M2 Kinzhal’; a nuclear-powered cruise missile, 9M730 ‘Burevestnik’; and a nuclear-powered, uncrewed underwater vehicle, ‘Poseidon’.[1]
Russian statements also outline the general rationale behind the modernisation plans. For example, President Putin stated in December 2025 that nuclear modernisation is ‘ensuring Russia’s strategic parity, security, and global standing’ and cited NATO as continuing to ‘actively prepare for the deployment of medium-range missiles, updating its nuclear munitions, modernising air and missile defence systems’.[2]
Last updated: 22 April 2026 18:43
The UK government has disclosed its high-level plans and a strategic rationale for modernising its nuclear arsenal, but has simultaneously increased ambiguity around its operational details in recent years.
The United Kingdom states it must modernise its nuclear arsenal in direct response to a ‘deteriorating security environment’. The 2023 Integrated Review Refresh asserts that the international context is more competitive and dangerous than at any time since the Cold War. It cites an ‘acute threat’ from Russia, an ‘epoch-defining and systemic challenge’ posed by China, and the proliferation of nuclear weapons and disruptive technologies by states like North Korea and Iran.[1]
Public, headline plans for modernising UK nuclear weapon systems and the nuclear weapons complex include:
— Building four new Dreadnought-class nuclear-armed ballistic missile submarines (SSBNs) to replace the current four Vanguard-class SSBNs, with the first-in-class HMS Dreadnought due to enter service in the early 2030s.
— Deploying on the Dreadnought SSBNs the US-designed and built Trident II D5LE submarine-launched ballistic missile (SLBM), as currently deployed on the Vanguard-class, to be replaced by the D5LE2 from the 2040s.[2][5]
— Purchasing twelve F-35A aircraft from the US to provide a ‘dual-capable’ (conventional and nuclear) air-launched nuclear capability using B61-11 US gravity bombs in support of NATO.
— Designing a replacement warhead, known as Project Astraea (A21/Mk7), in close coordination with the US W93 warhead programme to replace the current UK design (Holbrook/Mk4A).[3]
— Undertaking a massive, multi-billion-pound infrastructure modernisation initiative to support the design and production of a new warhead. This includes the Project MENSA warhead assembly/disassembly facility at the Atomic Weapons Establishment (AWE) Burghfield site; a High Explosive Fabrication Facility; and the Future Materials Campus (FMC) to manufacture, store, and recover nuclear materials for warhead components at AWE Aldermaston.[4]
— Modernising all parts of the nuclear weapons complex, including BAE Systems’ shipyard in Barrow-in-Furness, the next generation of facilities at Rolls-Royce’s Raynesway site in Derby, and the Royal Naval Armaments Depot (RNAD) Coulport, to build new facilities to support Astraea.[4]
— Exploring options to re-establish a nuclear fuel cycle for reactor fuel for defence purposes.[4]
However, very little detail has been disclosed on the capabilities, timelines, and decision-making on these projects.
The UK has maintained a moratorium on fissile material production for weapons purposes since 1995. New facilities at AWE are not for producing new plutonium or uranium. The modernisation programme involves using the UK’s existing stocks of fissile material.
Last updated: 22 April 2026 18:43
The United States generally discloses detailed plans for the modernization of each element of its nuclear arsenal, including warheads, delivery systems, nuclear warhead production, nuclear command and control, and the facilities, networks, and workforce that underpin them.
This degree of transparency can primarily be attributed to the fact that while presidential administrations can issue decisions and guidance about alterations to US nuclear forces, those alterations must be authorized and funds must be appropriated by Congress in order to execute them. As a result, presidential administrations must justify their proposals to Congress through detailed budgetary submissions, congressional testimony, and studies, and in compliance with laws that require certain types of disclosures.
By combining all of these various sources, it is possible to obtain a comprehensive picture of nearly every aspect of the US nuclear modernization program, with the exception of certain details or studies that remain classified (e.g. the Analysis of Alternatives report for the modernization of the intercontinental ballistic missile force, which would provide critical insight into the Department of Defense’s initial justifications for the program).
For example, the updated Nuclear Matters Handbook published by the Department of Defense in 2020 provides details on each warhead, delivery system, scientific and technical facility, and elements of nuclear command, control, and communications infrastructure that are currently being upgraded or modernized.[1]
In addition, the Department of Energy’s annual Stockpile Stewardship and Management Plan provides comprehensive details on each element of the nuclear security enterprise, including budgetary information and upgrades to individual warheads and facilities.[2] Detailed annual budgetary information is disclosed through presidential and service budget requests, which Congress then interrogates, authorizes, and appropriates.[3][4][5]
Despite a degree of classification for some aspects of nuclear modernization and the justifications for it, many documents are ultimately accessible via requests under the Freedom of Information Act.[6]
Last updated: 22 April 2026 18:43
China has on several occasions stated that it ‘unconditionally undertakes not to use or threaten to use nuclear weapons against non-nuclear-weapon States and nuclear-weapon-free zones’.[8]
These include the 1995 statement on negative security assurances from the five ‘nuclear weapon states’ as defined in the Nuclear Non-Proliferation Treaty([9] and the Chinese statement to the Conference on Disarmament (CD) in 2024,[10] among others.
China has also issued NSA statements in the context of its broader no-first-use (NFU) policy position.[2][3][4][5][6][7]
For example, a 2025 white paper published by the State Council Information Office affirmed, ‘China has always remained committed to the principle of no-first-use of nuclear weapons at any time and under any circumstances and unconditionally undertakes not to use or threaten to use nuclear weapons against non-nuclear-weapon states or nuclear-weapon-free zones’.[1]
Last updated: 22 April 2026 18:42
According to the 2022 law on Nuclear Forces Policy, the DPRK states that it shall not use or threaten to use nuclear weapons against non-nuclear-armed states if these states are not involved in ‘any aggression or attack against the DPRK in league with other nuclear-armed states].’[1]
In addition to this general provision that specifically mentions non-nuclear-armed states, Article 6 of the law on Nuclear Forces Policy outlines five conditions under which the DPRK would consider the use of nuclear weapons, and these conditions may be met regardless of whether an adversary is nuclear-armed or not:
1. if a nuclear attack or an attack by another weapon of mass destruction has been carried out or is judged to be imminent;
2. if a nuclear or non-nuclear attack on the state leadership or the state nuclear command apparatus by hostile forces has been carried out or is judged to be imminent;
3. if major strategic assets of the state have suffered a devastating military attack or when such an attack is judged to be imminent;
4. if there is an unavoidable operational need during a crisis to prevent the escalation or prolongation of war and to seize the initiative in the war; or
5. if there is no choice but to respond with nuclear weapons following the occurrence of a crisis with devastating consequences for the survival of the state or the lives and safety of the people.[1]
Last updated: 2 May 2026 05:54
Since 1982, France has provided negative security assurances to more than 100 non-nuclear-weapon states that comply with their non-proliferation obligations under the Nuclear Non-Proliferation Treaty (NPT).[1][2]
France specifies that its negative security assurances apply to countries that are parties to the NPT and in compliance with their non-proliferation obligations, and that these assurances do not affect France’s right of legitimate self-defence as recognised in the UN Charter.[3]
This commitment by France, as well as by the other four ‘nuclear-weapon states’ defined in the NPT, was enshrined in Resolution 984 adopted by the UN Security Council (UNSC) in 1995, and reiterated in UNSC Resolution 1887 (2009) and Resolution 2310 (2016).
In 2015, the negative assurances given by France to non-nuclear-weapon states were repeated by the President of the Republic, who recognised that it was ‘legitimate’ for these states to expect such assurances.[3]
On 4 August 2022, the United States, France and the United Kingdom published a joint statement at the NPT Review Conference reiterating their commitment to security assurances for non-nuclear-weapon states.[4][5]
Last updated: 22 April 2026 18:42
India’s nuclear doctrine clearly mandates a policy of no-first-use (NFU) of nuclear weapons and a negative security assurance (NSA) of ‘Non-use of nuclear weapons against non-nuclear weapon states’.[1]
However, India’s NFU and NSA pledges are conditional, as the nuclear doctrine also states, ‘However, in the event of a major attack against India, or Indian forces anywhere, by biological or chemical weapons, India will retain the option of retaliating with nuclear weapons’.[1] As written, this includes the possibility of Indian nuclear retaliation against non-nuclear-armed states that engage in such attacks.
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan supports the idea of Negative Security Assurance (NSA) for non-nuclear-armed states. At the Conference On Disarmament in Geneva, the country has advocated for a legally binding convention on NSAs, stating that this proposal ‘is most ripe for treaty negotiations and has the significant potential to create the necessary environment for confidence building and easing of tensions.’[1]
Last updated: 22 April 2026 18:42
Russia publicly discloses the circumstances in which it would consider the use of nuclear weapons against non-nuclear-armed states. As with the other four ‘nuclear weapon states’ defined in the Nuclear Non-Proliferation Treaty (NPT), Russia has issued a negative security assurance (NSA) committing not to use nuclear weapons against non-nuclear-armed states.[5] However, its NSA is not unconditional.
The Russian NSA from 1995 stated: ‘Russian Federation will not use nuclear weapons against non-nuclear-weapon States parties to the Treaty on the Non-Proliferation of Nuclear Weapons, except in the case of an invasion or any other attack on the Russian Federation, its territory, its armed forces or other troops, its allies or on a State towards which it has a security commitment, carried out or sustained by such a non-nuclear-weapon State in association or alliance with a nuclear-weapon State.”[4]
Similarly, the 2024 Russian nuclear doctrine,[1] which superseded the doctrine published in 2020,[2] outlines a list of conditions under which Russia would consider employment of nuclear weapons. These conditions may apply to non-nuclear-armed states.
The 2024 doctrine includes language asserting that Russia reserves the right to use nuclear weapons not only in response to a nuclear attack, but also to respond to a conventional aggression that creates a critical threat to the sovereignty and territorial integrity of Russia and Belarus. It also specifies that aggression against Russia and /or its allies by any non-nuclear state with the participation or support of a nuclear state is considered as their joint attack.[1]
At the 2025 Preparatory Committee meeting of the NPT, Russia stated that non-nuclear-weapon States that participate in alliances with nuclear powers or have concluded bilateral security agreements with them (states under the so-called ‘nuclear umbrella’) are excluded from the granting by Russia of any universal security assurances applicable to other States.[3]
Last updated: 22 April 2026 18:43
The UK government reiterated in 2021 that ‘The UK will not use, or threaten to use, nuclear weapons against any non-nuclear weapon state party to the Treaty on the Non-Proliferation of Nuclear Weapons 1968 (NPT). This assurance does not apply to any state in material breach of those non-proliferation obligations. However, we reserve the right to review this assurance if the future threat of weapons of mass destruction, such as chemical and biological capabilities, or emerging technologies that could have a comparable impact, makes it necessary.’[1]
This followed on from a 2015 statement that ‘The UK will not use, or threaten to use, nuclear weapons against any Non-Nuclear Weapons State party to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). This assurance does not apply to any state in material breach of those non-proliferation obligations. While there is currently no direct threat to the UK or its vital interests from states developing weapons of mass destruction, such as chemical and biological capabilities, we reserve the right to review this assurance if the future threat, development or proliferation of these weapons make it necessary.’[2]
In 2010, the UK government had stated that ‘We are now able to give an assurance that the UK will not use or threaten to use nuclear weapons against non-nuclear weapon states parties to the NPT. In giving this assurance, we emphasise the need for universal adherence to and compliance with the NPT, and note that this assurance would not apply to any state in material breach of those non-proliferation obligations. We also note that while there is currently no direct threat to the UK or its vital interests from states developing capabilities in other weapons of mass destruction, for example chemical and biological, we reserve the right to review this assurance if the future threat, development and proliferation of these weapons make it necessary.'[3]
Last updated: 22 April 2026 18:43
In 1994, at the Preparatory Committee for the 1995 Review and Extension Conference of the Nuclear Non-Proliferation Treaty (NPT), states engaged in a discussion relating to negative security assurances. In the context of that discussion, the United States emphasized that negative security assurances did not need to be unconditional, and that they would be given only to states that had renounced nuclear weapons development.[1]
In addition, since 1994, each successive US presidential administration has issued a Nuclear Posture Review (NPR), which describes US nuclear strategy, policy, posture, and forces. The most recent iteration of the NPR, issued in 2022, reaffirmed the longstanding policy with regard to negative security assurances (NSA) that 'the United States will not use or threaten to use nuclear weapons against non-nuclear weapon states that are party to the NPT and in compliance with their nuclear non-proliferation obligations.'[2]
In June 2025, the International Atomic Energy Agency (IAEA) issued a resolution finding that Iran was no longer in compliance with its NPT obligations.[4] As such, while the conditions that apply in relation to the United States’ NSA do not specifically refer to Iran, it is the country that most obviously breaches them. Moreover, the 2022 NPR states that 'U.S. policy is to prevent Iran from acquiring a nuclear weapon,'[2] and the most recent iteration of the US Nuclear Employment Strategy, issued in 2024, affirms that the United States 'is prepared to use all elements of national power to ensure that outcome.'[3]
Last updated: 22 April 2026 18:43
In a 2025 white paper published by the State Council Information Office, China reiterated it ‘has always remained committed to the principle of no-first-use of nuclear weapons at any time and under any circumstances and unconditionally undertakes not to use or threaten to use nuclear weapons against non-nuclear-weapon states or nuclear-weapon-free zones.’[4]
China occasionally discloses other details on its nuclear use policy but often in abstract rather than unequivocal terms. These disclosures are normally contained in white papers on national defence, security, or arms control published by the State Council Information Office.
The 2013 white paper represents the most explicit indication of the circumstances in which China would consider the use of nuclear weapons. It states, ‘If China comes under a nuclear attack, the nuclear missile force of the PLASAF will use nuclear missiles to launch a resolute counterattack either independently or together with the nuclear forces of other services’.[3] Related statements from other defence white papers since the 2010s include:
‘China pursues a nuclear strategy of self-defence, the goal of which is to maintain national strategic security by deterring other countries from using or threatening to use nuclear weapons against China’.[1]
‘PLARF is enhancing its credible and reliable capabilities of nuclear deterrence and counterattack, strengthening intermediate and long-range precision strike forces, and enhancing strategic counter-balance capability, so as to build a strong and modernized rocket force’.[2]
Last updated: 22 April 2026 18:42
The DPRK has twice disclosed its laws governing the use of nuclear weapons. The current law on ‘Nuclear Forces Policy’, published in 2022, outlines five conditions in which the DPRK would consider the use of nuclear weapons. These are:
1. if a nuclear attack or an attack by another weapon of mass destruction has been carried out or is judged to be imminent;
2. if a nuclear or non-nuclear attack on the state leadership or the state nuclear command apparatus by hostile forces has been carried out or is judged to be imminent;
3. if major strategic assets of the state have suffered a devastating military attack or when such an attack is judged to be imminent;
4. if there is an unavoidable operational need during a crisis to prevent the escalation or prolongation of war and to seize the initiative in the war; or
5. if there is no choice but to respond with nuclear weapons following the occurrence of a crisis with devastating consequences for the survival of the state or the lives and safety of the people.[3]
The 2022 law on Nuclear Forces Policy replaced an older law from 2013 entitled ‘On Consolidating the Position of Nuclear Weapons State for Self-Defence.’[1][2]
Last updated: 2 May 2026 05:54
French Presidents have disclosed in public speeches the country’s policy regarding the employment of nuclear weapons. Many official public documents, such as the 2025 Strategic Review, also formalise the French nuclear doctrine, which is strictly defensive and limited to extreme circumstances of self-defence. While the doctrine has adapted to changes in the international environment over the years, the willingness for Presidents to discuss the doctrine in public speeches has been consistent since Charles de Gaulle’s first speech on the matter in 1959.[1]
In 2026, President Macron reiterated the French policy regarding the employment of nuclear weapons.[2] This policy had previously been formalised in the National Strategic Review, updated in July 2025,[3] and in a document published by the Ministry of Armed forces in 2026.[4] Specifically, the employment of nuclear weapons is limited to ‘extreme circumstances of self-defence’, and the President is the only one mandated to determine if an attack, coming from a state, but regardless of its form (nuclear or not), endangers the vital interests of the country. If the president determines that an attack reaches that threshold, he or she may decide to employ nuclear weapons to inflict damage from which an adversary ‘could not recover.’
The French doctrine also states that if an adversary does not perceive that it has infringed upon France’s vital interests, a nuclear warning strike may be conducted to reestablish deterrence. France specifies that nuclear weapons are political weapons and refuses any notion of nuclear warfighting.[3]
Finally, French nuclear doctrine encompasses the concepts of shouldering, according to which conventional forces are necessary to increase the credibility of nuclear deterrence, and of ‘forward deterrence’, meaning that the French vital interests have a European dimension and more specifically, that eight countries are involved in a nuclear deterrence partnership with France (United Kingdom, Germany, Belgium, Netherlands, Denmark, Sweden, Poland, and Greece).[2]
Last updated: 22 April 2026 18:42
In 2003, the Cabinet Committee on Security declared that ‘the nuclear doctrine and operational arrangements governing India’s nuclear assets, should be shared with the public.’
The disclosure included statements that in line with India’s no-first-use (NFU) posture,
‘nuclear weapons will only be used in retaliation against a nuclear attack on Indian territory or on Indian forces anywhere’[...]
‘However, in the event of a major attack against India, or Indian forces anywhere, by biological or chemical weapons, India will retain the option of retaliating with nuclear weapons.’[1]
This posture was reaffirmed in July 2022, in response to a parliamentary question to the Minister for External Affairs.[2]
Regarding its policy on the deployment and launch-readiness of nuclear warheads, India has consistently highlighted the ‘unacceptable risk of accidental use’ that results from maintaining nuclear weapons on ‘hair-trigger alert’,[3] and has called for ‘immediate and urgent steps, such as de-alerting and de-targeting.’[3][4]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Through official statements and speeches by senior officials, Pakistan has publicly disclosed its doctrine of ‘full spectrum deterrence’, which is ‘designed to comprehensively deter large-scale aggression against mainland Pakistan’. This doctrine includes concepts that guide the country's nuclear weapons policies but does not elaborate specific situations in which Pakistan would consider the employment of nuclear weapons.
In the words of Lt. Gen. (Retd) Khalid Kidwai, an Advisor to the National Command Authority of Pakistan, the country’s nuclear doctrine is based on a ‘Full Spectrum Deterrence capability, while remaining within the larger philosophy of Credible Minimum Deterrence.’ It is explicitly framed in terms of deterring and countering threats from India, including India’s ‘advantages of relative conventional asymmetry.’[1][3] The doctrine features ‘seamless integration between nuclear strategy and conventional military strategy’, and a ‘large variety of strategic, operational and tactical nuclear weapons, on land, air and sea, which are designed to comprehensively deter large-scale aggression against mainland Pakistan.’[2]
According to Lt. Gen. (Retd) Kidwai, the Full Spectrum Deterrence doctrine implies:
‘That Pakistan possesses the full spectrum of nuclear weapons in three categories: strategic, operational and tactical, with full range coverage of the large Indian land mass and its outlying territories; there is no place for India’s strategic weapons to hide.
That Pakistan possesses an entire range of weapons yield coverage in terms of kilotons (KT), and the numbers strongly secured, to deter the adversary’s declared policy of massive retaliation; Pakistan’s ‘counter-massive retaliation’ can therefore be as severe if not more.
That Pakistan retains the liberty of choosing from a full spectrum of targets in a “target-rich India”, notwithstanding the indigenous Indian BMD or the Russian S-400, to include counter value, counter force and battlefield targets.’[1]
Last updated: 22 April 2026 18:42
Russia publicly discloses its policy regarding when the employment of nuclear weapons would be considered. Russia made its nuclear doctrine publicly available for the first time in 2020.[2]
The current nuclear doctrine — Fundamentals of State Policy of the Russian Federation on Nuclear Deterrence — was approved by an executive order of Russian President Vladimir Putin on 19 November 2024 and published by the Ministry of Foreign Affairs.[1] It modifies and adds further details to those disclosed in 2020 regarding the conditions under which Russia would consider the employment of nuclear weapons. Based on the 2024 doctrine, these conditions are:
“a. receipt of reliable data on the launch of ballistic missiles attacking the territories of the Russian Federation and (or) its allies;
b. employment of nuclear or other types of weapons of mass destruction by an adversary against the territories of the Russian Federation and (or) its allies, against facilities and (or) military formations of the Russian Federation located outside its territory;
c. actions by an adversary affecting elements of critically important state or military infrastructure of the Russian Federation, the disablement of which would disrupt response actions by nuclear forces;
d. aggression against the Russian Federation and (or) the Republic of Belarus as participants in the Union State with the employment of conventional weapons, which creates a critical threat to their sovereignty and (or) territorial integrity;
e. receipt of reliable data on the massive launch (take-off) of air and space attack means (strategic and tactical aircraft, cruise missiles, unmanned, hypersonic and other aerial vehicles) and their crossing of the state border of the Russian Federation.”
In its national report to the Review Conference of the Nuclear Non-Proliferation Treaty (NPT) in 2021, Russia stated that its doctrine ‘ensures the level of transparency and clearness with regard to the parameters of nuclear deterrence.’[3]
Last updated: 22 April 2026 18:43
The UK government does not set out specific conditions in which it would consider using nuclear weapons but says that it would do so ‘only in extreme circumstances of self-defence, including the defence of our NATO Allies.’[1]
The language of ‘extreme circumstances’ reflects wording in the 1996 Advisory Opinion of the International Court of Justice (ICJ) on the Legality of the Use or Threat of Use of Nuclear Weapons, which stated the ICJ ‘cannot reach a definitive conclusion as to the legality or illegality of the use of nuclear weapons by a State in an extreme circumstance of self-defence, in which its very survival would be at stake.'[2] In a 2006 statement, the UK government explicitly addressed the ICJ Advisory Opinion and noted, ‘The threshold for the legitimate use of nuclear weapons is clearly a high one.'[3]
However, the 2025 Strategic Defence Review affirmed, ‘The UK is deliberately ambiguous about precisely when, how, and at what scale it would contemplate the use of nuclear weapons. The UK does not publicise figures for its operational stockpile, deployed warhead, or deployed missile numbers. This posture enhances its deterrent effect by complicating the calculations of potential aggressors and reduces the risk of deliberate nuclear use by those seeking a first-strike advantage.’[8]
The United Kingdom eschews language of ‘sub-strategic’ nuclear use, stating that ‘the UK’s nuclear weapons are not designed for military use during conflict but instead to deter and prevent nuclear blackmail and acts of aggression against our vital interests that cannot be countered by other means’.[4] It asserts that UK nuclear weapons are a tool that aims ‘to deter the most extreme threats to our national security and way of life, and that of our NATO Allies, rather than a warfighting capability intended to achieve a tactical or battlefield military advantage in a conflict.’[5]
Finally, the UK government, like NATO, does not rule out the first use of nuclear weapons,[6] because ‘the credibility of the deterrent rests on the conviction that we would bring all means to bear to ensure the security of the UK and our allies.’[7]
Last updated: 22 April 2026 18:43
Since 1994, each successive US presidential administration has issued a Nuclear Posture Review (NPR), which describes US nuclear strategy, policy, posture, and forces. The most recent iteration of the NPR, issued in 2022, reaffirmed longstanding policy that the United States 'maintains a very high bar for nuclear employment,' and 'would only consider the use of nuclear weapons in extreme circumstances to defend the vital interests of the United States or its Allies and partners.'[1] However, the United States has traditionally not provided any specific details as to what constitute 'vital interests.'
This guidance was translated into the most recent iteration of the Nuclear Employment Strategy, which was issued in November 2024 and repeats the above lines verbatim.[2]
In addition, US nuclear declaratory policy leaves open the possibility of nuclear first-use, as the most recent NPR indicated that the adoption of a no-first-use policy 'would result in an unacceptable level of risk in light of the range of non-nuclear capabilities being developed and fielded by competitors that could inflict strategic-level damage to the United States and its Allies and partners.'[1] The 2024 Nuclear Employment Strategy elaborates on this further, noting that the United States 'does not depend on a launch-under-attack policy to ensure a credible response.'[2]
In a shift from previous guidance, the 2022 guidance requires the Department of Defense to 'assess the ability of non-nuclear capabilities to contribute to deterrence, and [...] integrate these capabilities into operational plans, as appropriate.' This is being done 'to advance the goal of reducing reliance on nuclear weapons…'[1]
Last updated: 22 April 2026 18:43
In 2009, China and Russia signed a bilateral pre-launch notification agreement for ballistic missiles and space launch vehicles, and this was extended in 2020.[2][3] According to a Russian government summary published in 2010, the agreement establishes ‘a reciprocal notification mechanism for planned and executed launches of ballistic missiles and space launch vehicles in Russia and China in order to avoid any unclear and unforeseen situations. Information on launches of ballistic missiles and space launch vehicles will be exchanged on a confidential basis.’[4]
In September 2024, before a scheduled ICBM launch test, China gave advanced notice to the United States and other states, reportedly including Australia, France, and New Zealand, even though there is no bilateral agreement obligating China to do so.[1]
Last updated: 22 April 2026 18:42
The DPRK has on occasion provided notifications to organizations such as the International Maritime Organization, International Telecommunications Union and International Civil Aviation Organization.[1][2] However, this is not a consistent practice for all its missiles tests and space launch activities.[3][4][5]
Last updated: 2 May 2026 05:54
France has been a signatory state of the Hague Code of Conduct against the Proliferation of Ballistic Missiles (HCoC) since its adoption in 2002 and notifies its ballistic missile tests and space launches in the framework of the Code. These are accessible to all states that subscribe to the HCoC via a dedicated website.
According to the French National Report submitted to the Preparatory Committee meeting of the Nuclear Non-Proliferation Treaty in 2025, between January 2015 and January 2025, France issued 97 pre-launch notifications, equal to the number of French space and ballistic missile launches conducted during that period. The report also noted that in fulfilment of one of the provisions of the HCoC, France hosted an inspection by international observers at the Guiana Space Centre in Kourou (French Guiana) in 2011. A second visit to Kourou was organized in December 2022.[1]
Nuclear exercises conducted by the French Air Force are announced ahead of time via the Notice to Airmen (NOTAM) system and planned in a predictable manner.[2]
Last updated: 22 April 2026 18:42
India issues advance notice of missile tests and military activities involving dual-capable weapon systems. In 2005, India entered into an agreement with Pakistan on the mutual pre-notification of surface-to-surface ballistic missile tests.[1] As part of the agreement, India also issues Notice to Airmen (NOTAM) and Navigational Warning for Mariners (NAVAREAs) to their respective authorities. The two countries also concluded a 1991 agreement on providing advance notice on military exercises and troop movements, including a timely clarification on the ‘assembly of formations, the extent, direction of the exercise and the duration’.[2]
While these agreements have stood the test of time, there have been rare instances of possible non-compliance. In 2024, Pakistan’s Foreign Office spokesperson Mumtaz Zahra Baloch claimed that India did not strictly adhere to the 3-day advance notification period for its test launch of a nuclear-capable Agni V missile.[3]
Last updated: 22 April 2026 18:45
Israel provides a minimal level of public information on missile tests, space launch activities, and military exercises, for the purposes of air and maritime safety. However, it generally does not give specific, detailed advance notice of launches, and, consistent with its policy of nuclear opacity, these notifications acknowledge nothing on the nuclear domain.
Last updated: 24 April 2026 08:16
Pakistan does not issue public notifications in advance of all missile tests and military exercises involving nuclear-capable systems.
However, both Pakistan and India do share information with each other through official channels as part of a bilateral agreement signed in 2005, which commits them to providing advance notification to each other of ballistic missile test launches, covering ‘land or sea launched, surface-to-surface ballistic missile[s]’. It does not cover cruise missiles, satellite launch vehicles, or military exercises involving nuclear and dual-capable weapons systems.[1]
The 2005 agreement commits each party to notify the other ‘no less than three days in advance of the commencement of a five day launch window within which it intends to undertake flight tests’. The agreement also commits the parties to issue ‘notice to airmen’ (NOTAMs) and ‘Navigational Areas’ (NAVAREAs) via their respective authorities.
Last updated: 22 April 2026 18:42
Russia issues advance notices for some of its missile tests, space launch activities, and military exercises involving nuclear and dual-capable systems. These notices are issued under different international and bilateral regimes. The notifications are made confidentially to the relative authorities and participants in the regimes.[1][2][6][7]
Russia provides the United States with advance notifications on missile launches under the 1988 Soviet-US Ballistic Missile Launch Notification Agreement.[1] Russia also provides the United States with advance notification on exercises that involve participation of heavy bombers under the 1989 Agreement on Reciprocal Advance Notification of Major Strategic Exercises.[2] These notifications were included in the framework of the now-expired New START agreement, and the Russian Ministry of Foreign Affairs stated in February 2023 that Russia would continue to provide these notifications even after suspending its participation in the New START Treaty.[3][4] At the 2023 Preparatory Committee meeting of the Nuclear Non-Proliferation Treaty (NPT), Russia framed the continued issuance of these notifications as ‘measures to maintain predictability and stability in the nuclear missile sphere.’[5]
Russia also provides advance notifications on missile launches and space launch vehicles to China under the bilateral 2009 Agreement on Notifications of Launches of Ballistic Missiles and Space Launch Vehicles, which was extended in 2021.[6][7]
Russia also participates in the Hague Code of Conduct against Ballistic Missile Proliferation (HCOC), under which subscribing states provide pre-launch notifications of ballistic missile and space launch vehicle tests. However, the regime is voluntary and the degree to which Russia issues notifications is not known.
Last updated: 22 April 2026 18:43
The UK participates in multilateral transparency arrangements, mainly through the Hague Code of Conduct against Ballistic Missile Proliferation (HCOC), which commits participating states to provide pre-launch notifications of any ballistic missile or space launch vehicle launches and annual declarations of ballistic missile and space launch policies.[1]
Notification is sent to the HCoC’s Immediate Central Contact (ICC) managed by Austria. This includes information such as the generic class of the missile, the planned launch window, the launch area, and the planned direction. This data is shared with all other HCoC subscribing states through a dedicated online platform.
The UK provides post-launch notification to the United Nations of space launches under the 1975 Convention on Registration of Objects Launched into Outer Space. The UK also issues Notices to Airmen (NOTAM)s and marine hazard area notices for rocket launches from UK Space Agency-licensed sites.
The UK does not issue public or international pre-notifications for patrols of its nuclear-capable ballistic missile submarines, training related to the Trident nuclear weapon systems, or joint NATO nuclear exercises such as the annual Steadfast Noon exercise. However, NATO does issue public statements on military exercises, including exercises involving nuclear assets.[2]
Last updated: 22 April 2026 18:43
The United States issues advance notice of long-range missile tests, space launch activities that might be mistaken for nuclear missile launches, and military exercises involving nuclear and dual-capable weapon systems, through three main avenues:
1. Pursuant to a 1988 bilateral US-Russia(USSR) treaty, the United States issues notifications of test launches of intercontinental ballistic missiles and submarine-launched ballistic missiles. These notifications include the area from which the launch will take place and the geographic coordinates of the planned impact area(s) of the reentry vehicle(s), and must be issued no less than 24 hours in advance of launch. These notifications, the details of which are not publicly disclosed, are issued through the National Nuclear Risk Reduction Centers of the two countries and do not cover shorter-range missile launches.[1]
2. The United States regularly issues press releases in advance of its long-range missile test launches and nuclear weapons exercises, as these are typically planned months or years in advance and correspond to a rigorous testing schedule. For example, on November 3rd, 2025, Vandenberg Space Force Base issued a press release stating that 'An operational test launch of an Air Force Global Strike Command unarmed Minuteman III intercontinental ballistic missile is scheduled between 11:01 p.m. to 5:01 a.m. Pacific Time, Nov. 4, from north Vandenberg.'[2]
3. The United States issues regular navigational warnings to airmen and mariners for each missile and rocket test that it conducts, pursuant to the Convention on International Civil Aviation and in support of the Global Maritime Distress and Safety System. These notifications provide specific information about the nature of the launch, the coordinates of the launch and impact areas, and the dates under which the warning remains in effect. However, these warnings do not indicate what type of missile is being launched.[3]
Last updated: 22 April 2026 18:43
China does not publicly disclose its positions on how it accounts for the impact of strategic, non-nuclear technologies in its doctrine on the employment of nuclear weapons.
Last updated: 22 April 2026 18:42
In its 2022 law on Nuclear Forces Policy, the DPRK discloses a range of circumstances in which it would consider using nuclear weapons.[1] These include situations in which the DPRK has suffered a strategic attack, or believes one is imminent, using non-nuclear means. The conditions are as follows:
1. if a nuclear attack or an attack by another weapon of mass destruction has been carried out or is judged to be imminent;
2. if a nuclear or non-nuclear attack on the state leadership or the state nuclear command apparatus by hostile forces has been carried out or is judged to be imminent;
3. if major strategic assets of the state have suffered a devastating military attack or when such an attack is judged to be imminent;
4. if there is an unavoidable operational need during a crisis to prevent the escalation or prolongation of war and to seize the initiative in the war; or
5. if there is no choice but to respond with nuclear weapons following the occurrence of a crisis with devastating consequences for the survival of the state or the lives and safety of the people.[1]
Last updated: 2 May 2026 05:54
France does not mention strategic non-nuclear technologies explicitly in its nuclear doctrine, however the French doctrine clearly indicates that the decision on whether or not to the employment of nuclear weapons in response to an attack does not depend on the type of technology used in the attack, but on the level of damage caused and whether it puts in jeopardy the vital interests of the French state. This can include attacks using non-nuclear strategic weapons, including chemical, biological, or large-scale conventional attacks.
The official French doctrine also mentions air and missile defence and deep strike capacities as technologies that may be used to support the credibility of nuclear deterrence. Therefore, these could also be considered as strategic non-nuclear technologies though the doctrine does not label them as such. However, the French nuclear doctrine preserves a fundamental barrier between conventional operations and a potential use of nuclear weapons.[1]
Last updated: 22 April 2026 18:42
India‘s public statements do not explicitly draw linkages between specific strategic, non-nuclear technologies and their implications for its nuclear deterrence doctrine, other than in relation to chemical and biological weapons. Specifically, the country’s official nuclear doctrine contains the assertion that ‘in the event of a major attack against India, or Indian forces anywhere, by biological or chemical weapons, India will retain the option of retaliating with nuclear weapons.’[9]
However, Indian strategic thinking emphasises ‘highly effective conventional military capabilities that ‘shall be maintained to raise the threshold of outbreak of conventional military conflict as well as that of threat or use of nuclear weapons’ as stated by the former Minister of State for Defence, Shri MM Pallam Raju in a 2008 address.[8] This suggests that India will continue to advance its conventional capabilities, including investments in strategic non-nuclear technologies, as a part of its approach to practicing and operationalising nuclear deterrence.
In this regard, India regularly discloses its modernisation and defence plans for its military and conventional warfighting, including capabilities that can be categorised as strategic, non-nuclear technologies. These disclosures include dual-use systems such as updates on procurement plans for stealth fighter jets,[1] indigenous production of long-range and hypersonic missiles,[2] Anti-Satellite (ASAT) weapon systems,[3] and precision-guided munitions.[4]
Further, in May 2025, the Indian Ministry of Defence announced its plans to clear the batch of next-generation, precision-strike, supersonic Brahmos missiles with an increased range of up to 800 km.[5][6] Additionally, the Indian Cabinet Committee on Security approved the indigenous construction of nuclear-powered attack submarines (SSNs) in 2024.[7]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan has not disclosed any information regarding how it accounts for and responds to strategic, non-nuclear technologies in its doctrine on the employment of nuclear weapons.
Last updated: 22 April 2026 18:42
Russia publicly discloses how it accounts for and responds to strategic, non-nuclear technologies in its doctrine on the employment of nuclear weapons.
The current version of Russia’s nuclear doctrine (Fundamentals of State Policy of the Russian Federation on Nuclear Deterrence) was approved by executive order of the President in November 2024 and published in English and Russian.[1] It lists conditions under which Russia may consider the employment of nuclear weapons. These include a specification that nuclear use may be considered in response to the use of specific strategic, non-nuclear technologies.
The 2024 doctrine states that nuclear deterrence is intended to neutralise the threat of ‘possession and deployment by a potential adversary of missile defence systems and assets, intermediate- and shorter-range cruise and ballistic missiles, high-precision non-nuclear and hypersonic weapons, unmanned combat vehicles of various basing modes, directed energy weapons that can be used against the Russian Federation.’[1]
It also specifies that Russia may use nuclear weapons in response to ‘receipt of reliable data on the massive launch of air and space attack means (strategic and tactical aircraft, cruise missiles, unmanned, hypersonic and other aerial vehicles) and their crossing of the state border’ of Russia.[1]
Last updated: 22 April 2026 18:43
The UK government does not disclose in detail how it accounts for or would respond to strategic, non-nuclear technologies (for example, cyber capabilities, anti-satellite weapons, hypersonic or precision-strike systems) in its doctrine governing the employment of nuclear weapons.
However, the United Kingdom does acknowledge that emerging strategic, non-nuclear technologies could influence its nuclear deterrence posture and might, in extreme circumstances, affect the conditions under which it would consider nuclear use. In 2021, the UK government stated it reserved the right to review its negative security assurance in light of ‘emerging technologies that could have a comparable impact’ to a weapon of mass destruction. It reiterated that it will remain deliberately ambiguous about precisely when, how and at what scale it would contemplate the use of nuclear weapons.[1]
Last updated: 22 April 2026 18:43
Since 1994, each US presidential administration has issued a Nuclear Posture Review (NPR), which describes US nuclear strategy, policy, posture, and forces. The policies articulated in the most recent NPR, published in 2022, were translated into an updated version of the US Nuclear Employment Strategy published in 2024. The guidance in both documents noted explicitly that the role of US nuclear weapons includes deterring ‘strategic attacks’.
The 2022 NPR did not define ‘strategic attack’, but stated, ‘Consistent with prior reviews, our nuclear strategy accounts for existing and emerging non-nuclear threats with potential strategic effect for which nuclear weapons are necessary to deter.'[1] However, the 2018 NPR had described strategic non-nuclear attacks as follows: ‘Significant non-nuclear strategic attacks include, but are not limited to, attacks on the U.S., allied, or partner civilian population or infrastructure, and attacks on U.S. or allied nuclear forces, their command and control, or warning and attack assessment capabilities.'[3] The 2018 NPR also listed 'chemical, biological, cyber, and large-scale conventional aggression' as examples of 'non-nuclear strategic threats.'[3]
The 2024 Nuclear Employment Strategy affirmed that ‘The roles of nuclear weapons in United States strategy are to deter strategic attack, assure allies and partners, and enable achievement of national objectives in extreme circumstances if deterrence fails…’ and defined a strategic attack as ‘a nuclear attack of any scale as well as a significant, high-consequence, non-nuclear attack that has strategic-level effect.’[2]
It is important to note that these documents do not state that the United States necessarily would use nuclear weapons in response to these types of attacks, but rather that it might do so.
Last updated: 22 April 2026 18:43
China does not disclose its total number of nuclear warheads, either actively deployed or in storage, nor does it comment on others' assessments of that number.
Last updated: 22 April 2026 18:42
The DPRK government does not disclose the total number of nuclear warheads in its arsenal, nor any details regarding the numbers of warheads in different functional categories. In December 2022, however, Kim Jong Un emphasized the intention to pursue ‘an exponential increase of the country’s nuclear arsenal’.[1]
Last updated: 2 May 2026 05:54
Until March 2026, France consistently indicated that it possessed less than 300 nuclear warheads, both in written documents and in Presidential speeches. However, in a significant policy change, President Emmanuel Macron announced on 2 March 2026 that this number would be increased and that it would no longer be made public.[6]
The first time the French Government disclosed precise numbers for its nuclear stockpile was in 1994, when President François Mitterrand publicly stated that France possessed almost 500 weapons.[1] In 2008, President Nicolas Sarkozy mentioned the reductions in the stockpile carried out since the end of the Cold War and indicated that the French arsenal would be composed of less than 300 nuclear warheads from that time forward.[2] Presidents François Hollande and Macron reiterated this statement in 2015 and 2020, respectively.[3][4] The approximate data was also available in France’s transparency reports in the context of the Nuclear Non-Proliferation Treaty.[5]
Last updated: 22 April 2026 18:42
The Indian government does not disclose the total number of nuclear warheads in its arsenal, or any details on the sites used for production and storage of nuclear warheads. India pursues a policy of Credible Minimum Deterrence, meaning the country maintains a nuclear arsenal that the government believes is sufficient to provide maximum credibility with minimum forces dedicated to the role.[1]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan has never shared the total number of nuclear warheads in its nuclear arsenal, including those that are deployed, in storage, or awaiting dismantlement.
Last updated: 22 April 2026 18:42
Russia does not publicly disclose the total number of nuclear warheads in its arsenal.
Under the now-expired New START Treaty, Russia provided data to the United States on its numbers of deployed strategic warheads across intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs), as well as the number of deployed heavy bombers (each heavy bomber was counted as one nuclear warhead under the New START counting rules), until Russia suspended its participation in the Treaty in February 2023. New START had bilateral verification provisions but was not subject to verification by any third party.[1]
Aggregate figures derived from data exchanges under New START were published twice a year by the Russian Ministry of Foreign Affairs. The latest disclosure provides data as of 1 September 2022.[3]
Russian President Vladimir Putin emphasised the value of transparency provided by New START, stating that it ‘played a role in maintaining balance and predictability in the sphere of strategic offensive weapons’.[4] Russia suspended its participation in the Treaty citing what it described as US policies aimed at undermining Russia’s national security. In doing so, Russia also pointed to Ukrainian attacks on several facilities covered by the Treaty, accusing the United States of assisting these attacks while simultaneously seeking inspection access.[5]
As a ‘nuclear-weapon state’ under the Nuclear Non-Proliferation Treaty (NPT), Russia has submitted national reports on its implementation of the NPT as part of the Treaty’s review process at each Review Conference since 2005. These reports provide historic information on reductions in Russian nuclear strategic and non-strategic warheads – both unilateral reductions and those conducted under previous arms control treaties with the United States.[2]
Last updated: 22 April 2026 18:43
The UK government does not disclose an exact, total number of nuclear warheads in its stockpile. Instead, it has regularly disclosed a ‘warhead ceiling’. The most recent disclosure was in the 2021 Integrated Review of Security, Defence, Development, and Foreign Policy. This stated that ‘in recognition of the evolving security environment, including the developing range of technological and doctrinal threats,’ the earlier ceiling of 225 is ‘no longer possible, and the UK will move to an overall nuclear weapon stockpile of no more than 260 warheads.’ The Integrated Review also stated, however, that the UK government intended to extend its ‘long-standing policy of deliberate ambiguity and no longer give public figures for our operational stockpile, deployed warhead or deployed missile numbers.’[1] The most recent Strategic Defence Review and National Security Strategy, published by the UK government in 2025, did not recommend a warhead ceiling.[2]
The announcement in 2021 signalled the end of a series of post-Cold War reductions in the overall UK nuclear weapon stockpile as follows:
—In 1988, the UK government announced its intention to limit the total number of warheads for the new Trident system to 512 and that it would deploy no more than 128 warheads per submarine.[3] This was reduced again in 1995 to a total of 300 warheads with a maximum of 96 per submarine, and later to a maximum of 60 warheads per submarine.[4]
—In 1998, the government announced a reduction in the number of operationally available Trident warheads to no more than 200.[5]
—In 2006 the government announced that it would reduce the number of operationally available warheads by 20% to 160.[6]
—In the 2010 UK Strategic Defence and Security Review, the UK government announced its intention to reduce its overall nuclear warhead stockpile ceiling from not more than 225 to not more than 180 by the mid 2020s, and to reduce its operationally available warheads from fewer than 160 to no more than 120.[7] In 2015, the statement from 2010 was repeated in the government’s Strategic Defence and Security Review.[8]
Last updated: 22 April 2026 18:43
The United States periodically discloses figures for its current nuclear stockpile, annually dismantled warheads, and retired warheads awaiting dismantlement.
It did this for the first time in 2010, when it declassified the entire history of the US nuclear stockpile, including the annual stockpile size, the number of dismantled warheads since 1994, and the number of retired warheads awaiting dismantlement.[4]
The United States continued to disclose this data on an annual basis until 2019, when the US Department of Defense denied successive declassification requests.[5] In 2021, transparency was restored and the figures from the missing years were disclosed.[6] Another disclosure of these figures was made in 2024, similarly restoring the missing data from the previous years.[1] It appears the United States is shifting towards disclosing these figures on an ad hoc, rather than a scheduled basis.
In addition, as a party to the now-expired New START agreement between Russia and the United States, which limited numbers of deployed strategic warheads and launchers,[7] the United States previously released its aggregate numbers of strategic warheads on deployed intercontinental ballistic missiles, submarine-launched ballistic missiles, and nuclear warheads on deployed heavy bombers (each bomber counted as one warhead under the Treaty’s counting rules). This release occurred twice a year throughout most of the duration of the treaty.[2]
Although the United States did not publish the New START data in disaggregated format, this data was available upon request from the Department of State throughout this time. Following Russia's unilateral suspension of New START in February 2023, the United States disclosed one final set of deployment-related treaty data from March 2023.[3] It has not released any deployment data since then.
Last updated: 22 April 2026 18:43
China does not disclose the yields of its various nuclear warheads.
Last updated: 22 April 2026 18:42
The DPRK has not disclosed the exact yields of its nuclear warheads. However, state media (KCNA) has reported on a series of inspections conducted by the DPRK Supreme Leader Kim Jong Un during the development of the country’s nuclear arsenal, in which details about various warheads were disclosed.
For example, following an inspection conducted by Kim in March 2016, KCNA reported that the ‘nuclear warheads have been standardized to be suitable for ballistic missiles by miniaturizing them’ and ‘with a Korean-style structure of mixed charge.’[1]
Following the sixth nuclear test in 2017, KCNA mentioned a yield range, describing the warhead that had been tested as a ‘hydrogen bomb’ with a yield ‘which is adjustable from tens of kilotons to hundreds of kilotons.’ The report also stated the test demonstrated a ‘strategic purpose’ for the weapons ‘to deliver a super-powerful EMP attack over a vast area.’[2]
Another KCNA report from March 2023 referred to ‘new tactical nuclear weapons according to the purpose of the operation and targets, interchangeability with different weapons systems.’[3]
Last updated: 2 May 2026 05:54
France does not currently reveal any information on the explosive yields of the two types of nuclear warheads it possesses: the Oceanic Nuclear Warhead (TNO) used on submarine-launched ballistic missiles (SLBMs) and the Airborne Nuclear Warhead (TNA) used on air-launched cruise missiles. However, French doctrine establishes that all French nuclear weapons are deemed to be ‘strategic’,[1] and thus, they might not reach the low yield levels more commonly associated with sub-strategic or tactical nuclear weapons.
President François Mitterrand declared in 1994 that a warhead coupled to the SLBMs used by France at that time had a yield of 150 kilotons, and that the yield of warheads deployed on French cruise missiles at that time was 300 kilotons.[2] Since that time, no information has been published at the official level on the issue of nuclear warhead yields, and information reported by the media is never backed by credible assessments.
Last updated: 22 April 2026 18:42
The Indian government does not disclose the yields of its various warheads, but it has revealed information about the yields of the nuclear test explosions it conducted in May, 1998.
Those explosions, conducted in the Pokhran desert, included five devices of different yields including sub-kiloton devices of 0.2 kt, 0.3 kt and 0.5 kt, and larger yields including a 15 kt fission device and a 45 kt thermonuclear device [1]. Later the same month, then-Prime Minister Atal Bihari Bajpayee declared India would henceforth observe a nuclear explosion test moratorium.[2]
Last updated: 22 April 2026 18:45
Israel has a strict, long-standing policy of refusing to confirm or deny anything, either directly or indirectly, about its nuclear weapons status. The Israeli government treats any information that may have significance in that regard as classified and stringently enforces its domestic censorship.
Last updated: 24 April 2026 08:16
Pakistan does not disclose the explosive yields of its nuclear warheads.
Last updated: 22 April 2026 18:42
Russia does not publicly disclose the yields of its various nuclear warheads.
Last updated: 22 April 2026 18:43
The explosive yields of UK warheads are classified([1]. However, the House of Commons Library stated in a report in 2016 that the UK Holbrook warhead ‘is believed to be closely related to the American W76 warhead, a thermonuclear warhead in the 80-100 kiloton range.'[2]
This is because the UK Holbrook warhead is understood to be an Anglicised version of the US W76-1 warhead. For example, Franklin Miller KGB, Special Advisor to President George W Bush and Senior Director for Defense Policy and Arms Control, described the UK warhead as ‘their W76 variant’.[3]
The US deploys the W76-1 warhead on its Trident II (D5) submarine-launched ballistic missiles (SLBMs). The United Kingdom also deploys its Holbrook warhead on Trident II (D5) SLBMs under a lease arrangement for 58 missile bodies drawn from a common pool in the US.[4] The UK warhead must therefore match the size, mass, centre of gravity and other characteristic requirements for the US-supplied warhead re-entry body designed to operate with the Trident missile.
The Holbrook warhead can also be detonated at a lower yield, described by the government in the 1990s as a ‘sub-strategic’ option,[5] using a variant of the warhead with no secondary and detonating only the primary stage only. The government confirmed in 1997 that ‘The UK has some flexibility in the choice of yield for the warheads on its Trident missiles’.[6] The US deployed a reduced yield variant of its W76 warhead (the W76-[2] in 2019 by configuring a small number of existing warheads for primary-only detonation.[7] It is not clear if a low-yield variant exists within the current UK stockpile.
Last updated: 22 April 2026 18:43
The United States does not disclose the exact yields of the warheads in its current arsenal. However, it does occasionally disclose information about current warheads that would help analysts make educated assumptions about their yields, by disclosing information about warhead designs or yields relative to other weapons. For example, in its announcement on the development of the new B61-13 gravity bomb, the Department of Defense stated that the weapon would 'have a yield similar to the B61-7, which is higher than that of the B61-12.'[1]
The United States has also declassified the exact yields of many of its nuclear tests, as well as the yields of some nuclear weapons that are no longer in the US arsenal.[2][3][4] For example, the yield of the B53—once the highest-yield nuclear weapon in the US arsenal—was officially declassified in 2014 and revealed to be 9 megatons, although it had already been retired and dismantled by that time.[5]
In addition, the United States has declassified the total annual megatonnage of explosive force in its arsenal between 1945 (0.04 megatons) and 1994 (2,375.3 megatons); the year of the largest stockpile megatonnage was 1960 (20,491.17 megatons).[6] While this dataset was not disaggregated by weapon, it can be used to make analytical estimates for individual warheads.
Last updated: 22 April 2026 18:43