The Stockholm International Peace Research Institute (SIPRI) launched its annual assessment of the state of armaments, disarmament and international security. 

SIPRI Yearbook 2025 revealed that a dangerous new nuclear arms race is emerging at a time when arms control regimes are severely weakened.

Key points on nuclear arms race:

• Nearly all of the nine nuclear-armed states — the United States, Russia, the United Kingdom, France, China, India, Pakistan, North Korea and Israel — continued intensive nuclear modernisation programmes in 2024, upgrading existing weapons and adding newer versions.

• The signs are that a new arms race is gearing up that carries much more risk and uncertainty than the last one.

• The rapid development and application of an array of technologies — for example in the fields of artificial intelligence (AI), cyber capabilities, space assets, missile defence and quantum — are radically redefining nuclear capabilities, deterrence and defence, and thus creating potential sources of instability. 

• Advances in missile defence and the oceanic deployment of quantum technology could ultimately have an impact on the vulnerability of key elements of states’ nuclear arsenals. 

• Furthermore, as AI and other technologies speed up decision making in crises, there is a higher risk of a nuclear conflict breaking out as a result of miscommunication, misunderstanding or technical accident.

• Revitalised national debates in Europe, the Middle East and East Asia about nuclear status and strategy suggest there is some potential for more states to join the nuclear club. 

• The signs are that a new qualitative nuclear arms race is gearing up and, compared with the last one, the risks are likely to be more diverse and more serious.

• The explosive material utilised in nuclear weapons is fissile material, either highly enriched uranium (HEU) or separated plutonium. China, France, Pakistan, Russia, the UK and the US have produced both HEU and plutonium for use in their nuclear weapons. India and Israel have produced mainly plutonium. North Korea has produced plutonium for use in nuclear weapons but is believed to be producing HEU for nuclear weapons as well. All states with a civilian nuclear industry are capable of producing fissile materials.

• A return to an era of reductions to the global nuclear arsenal, however, requires agreement among the US, Russia and China. 

• A new, general understanding is needed that nuclear weapons do not buy security and that their existence demands balanced behaviour by political leaders. Initial small steps towards reducing risk could form guardrails against disaster. 

• Together with the voices of an informed public, they could also be part of building pressure on the three great powers to take the next steps in reducing their nuclear arsenals.

A brief glimpse on nuclear forces

• At the start of 2025, nine states together possessed approximately 12,241 nuclear weapons, of which 9,614 were considered to be potentially operationally available. An estimated 3,912 of these warheads were deployed with operational forces, including about 2,100 that were kept in a state of high operational alert on ballistic missiles.

• Russia and the US together possess around 90 per cent of all nuclear weapons. The sizes of their respective military stockpiles (usable warheads) seem to have stayed relatively stable in 2024 but both states are implementing extensive modernisation programmes that could increase the size and diversity of their arsenals in the future. If no new agreement is reached to cap their stockpiles, the number of warheads they deploy on strategic missiles seems likely to increase after the bilateral 2010 Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START) expires in February 2026.

• SIPRI estimates that China now has at least 600 nuclear warheads. China’s nuclear arsenal is growing faster than any other country, by about 100 new warheads a year since 2023. By January 2025, China had completed or was close to completing around 350 new intercontinental ballistic missile (ICBM) silos in three large desert fields in the north of the country and 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 reaches the maximum projected number of 1,500 warheads by 2035, that will still amount to only about one-third of each of the current Russian and US nuclear stockpiles.

• Although the United Kingdom is not thought to have increased its nuclear weapon arsenal in 2024, its warhead stockpile is expected to grow in the future, after the 2023 Integrated Review Refresh confirmed earlier plans to raise the ceiling on warhead numbers.

• According to the report, India slightly expanded its nuclear arsenal in 2024 and continued to develop new types of nuclear delivery systems. SIPRI pegged the number of nuclear warheads in the Indian arsenal at 180 as of January 2025. India’s new ‘canisterized’ missiles, which can be transported with mated warheads, may be capable of carrying nuclear warheads during peacetime, and possibly even multiple warheads on each missile, once they become operational. 

• Pakistan also continued to develop new delivery systems and accumulate fissile material in 2024, suggesting that its nuclear arsenal might expand over the coming decade.

• North Korea continues to prioritise its military nuclear programme as a central element of its national security strategy. SIPRI estimates that the country has now assembled around 50 warheads, possesses enough fissile material to produce up to 40 more warheads and is accelerating the production of further fissile material. South Korean officials warned in July 2024 that North Korea was in the ‘final stages’ of developing a ‘tactical nuclear weapon’. In November 2024, North Korean leader Kim Jong Un called for a ‘limitless’ expansion of the country’s nuclear programme. 

• Israel, which does not publicly acknowledge possessing nuclear weapons, is also believed to be modernising its nuclear arsenal. In 2024 it conducted a test of a missile propulsion system that could be related to its Jericho family of nuclear-capable ballistic missiles. Israel also appears to be upgrading its plutonium production reactor site at Dimona.

Manorama Yearbook app is now available on Google Play Store and iOS App Store