New Delhi: The nine nuclear-armed states which includes India, the United States, Russia, the United Kingdom, France, China, Pakistan, the Democratic People’s Republic of Korea (North Korea) and Israel—continued programmes to modernise and enhance their nuclear arsenals in 2025, and most deployed new nuclear-armed or nuclear-capable weapon systems during the year, says the latest report of Stockholm International Peace Research Institute(SIPRI).
According to this report, India is believed to have once again slightly expanded its nuclear arsenal in 2025 and continued development of new types of nuclear delivery systems. The modernisation programme is increasingly focused on developing long-range weapons capable of reaching targets throughout China, although planning also continues to be focused on India’s long-standing rivalry with Pakistan. Pakistan continued to develop new delivery systems and accumulate fissile material in2025, suggesting that its nuclear arsenal might expand over the coming decade. The brief armed conflict between India and Pakistan in May 2025saw India attacking Pakistani air- and missile bases that are likely to have nuclear-related roles, but both sides took steps to avoid escalation.
Of the total global inventory of an estimated 12,187 warheads in January 2026, about 9745 were in military stockpiles for potential use. An estimated 4012 of those warheads were deployed with missiles and aircraft and the rest were in central storage. Between 2100 and 2200 of the deployed warheads were kept in a state of high operational alert on ballistic missiles. Nearly all of these warheads belonged to Russia or the USA, and to a lesser extent France and the UK, but China and India may now occasionally deploy a small number of warheads mounted on missiles during peacetime.
‘Influential voices, including some world leaders, are advocating nuclear weapons as a guarantee against attack by a hostile state. But making national defence and security strategies dependent—or more dependent—on nuclear weapons could significantly increase nuclear risks,’ said SIPRI Director Karim Haggag. ‘The dangers associated with nuclear weapons are growing due to advances in weapon technology, the breakdown of nuclear arms control and heightened geopolitical tensions, among a range of other factors. At the same time, world events—not least the outbreak of conflict between nuclear-armed India and Pakistan—are challenging nuclear deterrence logic.’
Since the end of the cold war, the gradual dismantlement of retired warheads by Russia and the USA has normally outstripped the deployment of new warheads, resulting in an overall year-on-year decrease in the global inventory of nuclear weapons. This trend is likely to be reversed in the coming years, as the pace of dismantlement is slowing, while the deployment of new nuclear weapons is accelerating.
‘The evidence is growing that the nuclear weapon states are sidelining, and even walking away from, their disarmament commitments and are instead flexing their nuclear muscles,’ said Hans M. Kristensen, Associate Senior Fellow with SIPRI’s Weapons of Mass Destruction Programme and Director of the Nuclear Information Project at the Federation of American Scientists (FAS). ‘By reaching for nuclear solutions, states are creating new risks and fuelling arms-race dynamics.’
Russia and the USA together possess around 83 percent of all stockpiled nuclear warheads (i.e. useable warheads). This combined share is shrinking somewhat due to the growth in the world’s other nuclear arsenals. The sizes of the Russian and US military stockpiles appear to have stayed relatively stable in 2025 but both states’ extensive modernisation programmes seem likely to increase the size and diversity of their arsenals in the future. The USA’s comprehensive nuclear modernisation programme is progressing but in 2025 faced continued planning and funding challenges that are likely to further delay and significantly increase the cost of the programme.
Moreover, the effort to add new non-strategic nuclear weapons to the US arsenal will place further budgetary and logistical stress on the modernisation programme, a trend that will deepen further as a result of the Trump administration’s plans for the Golden Dome missile-defence system, which it is estimated will cost $1.2 trillion. Russia’s nuclear modernisation programme is also facing challenges. In 2025 another test launch of the Sarmat intercontinental ballistic missile (ICBM) being developed by Russia failed, while Western economic sanctions and competing demands linked to the war in Ukraine seem to have affected the programme. Another troubled programme, the new Burevestnik nuclear-powered ground-launched cruise missile, was claimed to have achieved a successful flight test in 2025 to a distance of over 14,000 kilometres, after several failures.
Russia has also started building a forward-operating base for its dual-capable Oreshnik intermediate-range ballistic missile (IRBM) in Belarus, and Oreshnik missiles have been used against Ukraine with conventional warheads, most recently in May 2026. The significant increase in Russia’s non-strategic nuclear warheads predicted by the USA in 2020 has still not materialised.
Both Russian and US deployments are likely to rise in the years ahead. The Russian increase would mainly happen as a result of modernising the country’s remaining strategic forces to carry more warheads on each missile. The US increase could happen as a result of more war heads being deployed to existing launchers, empty launchers being reactivated and new non-strategic nuclear weapons being added to the arsenal. Nuclear advocates in the USA are pushing for these steps as are action to China’s new nuclear deployments. Furthermore, with the expiry of the bilateral 2010 Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START) in February this year, uncertainty is increasing about the future direction of US and Russian strategic nuclear force levels.
SIPRI estimates that China now has around 620nuclear warheads. China is expanding its nuclear arsenal faster than any other country and showcased several new nuclear systems during its 2025 military parade. By January 2026, China had loaded hundreds of missiles into three large missile silo fields in the north of the country, while working to complete 30silos in three mountainous areas in the east. Depending on how it decides to structure its forces, China could potentially have at least as many ICBMs as either Russia or the USA by the turn of the decade. Yet even if China surpasses 1000 warheads by 2030, that will still amount to only about one quarter of each of the current Russian and US nuclear stockpiles.
Although the UK is not thought to have increased its nuclear weapon arsenal in 2025, its operational warhead stockpile is expected to grow in the future, after the 2021 Integrated Review announced the UK’s intention to raise the ceiling on warhead numbers. The 2025 Strategic Defence Review reiterated the UK’s 2021 policy change of no longer publicising the size of its nuclear arsenal, reducing transparency concerning the UK’s arsenal. Also, in 2025 the UK announced its intention to buy 12 nuclear-capable F-35A combat aircraft from the USA, and equip them with US nuclear bombs, in order to join NATO’s nuclear sharing arrangements. The plan walks back the decision from the 1990sto denuclearise the Royal Air Force.
In 2025 France continued to upgrade its nuclear-powered ballistic missile submarine (SSBN) force, introducing its enhanced M51.3submarine-launched ballistic missile (SLBM) and pressing ahead with development of a third-generation SSBN. The government also announced plans to establish a new nuclear airbase in eastern France for two new nuclear-capable Rafale aircraft squadrons equipped with France’s next generation hypersonic nuclear air-launched cruise missile. In March 2026 President Emmanuel Macron announced that he had ordered an increase in the number of warheads in the French nuclear arsenal and that the government would no longer publicly communicate the size of its arsenal.
North Korea continues to develop its nuclear capabilities to fulfil its stated goal of ‘exponentially’ expanding its nuclear arsenal. SIPRI estimates that the country has possibly assembled around 60 warheads, possesses enough fissile material to produce at least 30 more and is accelerating the production of fissile material. In 2025 North Korea continued to unveil and test new missile systems, including the ‘next-generation’ solid-fuelledHwasong-20 ICBM, as well as medium-range, highly manoeuvrable systems designed to evade missile defences. Israel—which does not publicly acknowledge possessing nuclear weapons—is also believed to be modernising its nuclear arsenal.
In 2025 Israel intensified construction at a new site at the Negev Nuclear Research Centre near Dimona, which could be related to its nuclear capabilities. While nuclear programmes have always been shrouded in secrecy, in recent years nuclear-armed states have shifted further towards strategic ambiguity and opacity even as they modernise and expand their nuclear forces. This trend seems likely to continue in the post-New START world. At the same time, there is a lack of strategic dialogue or direct communication among certain nuclear-armed states.
‘Along with the reduction in transparency and the loss of diplomatic channels for crisis management, the drift towards authoritarianism in some nuclear-armed states is contributing to even greater unpredictability,’ said Matt Korda, Associate Senior Researcher with SIPRI’s Weapons of Mass Destruction Programme and Associate Director for the Nuclear Information Project at FAS. ‘We can no longer assume that leaders operating within such systems will receive accurate data during nuclear crises, nor that they willact rationally during periods of heightened tension.’
Developments and national debates in East Asia, Europe and the Middle East during 2025 also hinted at a growing role for nuclear weapons in several non-nuclear-armed states’ security and defence strategies. In 2025 several European states, including Germany, indicated a desire to supplement NATO nuclear-sharing arrangements focused on US weapons with similar arrangements with France and the UK. President Macron announced in March 2026 that France was already in dialogue with Germany and the UK and that several other European states were interested in joining. In addition, both Belarus and Russia have repeatedly claimed that Russia has deployed nuclear weapons on Belarusian territory, and in December 2025 Russia released a video showing the dual-capable Oreshnik IRBM operating inside Belarus. These developments are unfolding at a time when the global nuclear non-proliferation regime is weakening.
The 2026 Review Conference of the states parties to the 1968 Nuclear Non-Proliferation Treaty, which ended on 22 May, was the third Review Conference in a row to close without issuing a final outcome document. ‘The fact that the states parties to the Non-Proliferation Treaty once again failed to reach agreement on an outcome document is another blow to the grand bargain at the heart of the treaty: that other states will not develop their own nuclear forces if the nuclear weapon states move towards disarmament,’ said SIPRI Director Karim Haggag. ‘The absence of a successor agreement to New START, the modernisation of nuclear forces and plans to increase the deployment of nuclear weapons are all likely to further undermine the legitimacy of the Non-Proliferation Treaty. This will make it more difficult for the states parties to collectively address the many challenges across the nuclear landscape, including in the Middle East and East Asia.’
