As geopolitical relations deteriorate, nuke nations start strengthening their arsenals

While Pakistan remains the main focus of India’s nuclear deterrent, India appears to be placing growing emphasis on longer-range weapons, including those capable of reaching targets throughout China

The nine nuclear-armed states—the United States, Russia, the United Kingdom, France, China, India, Pakistan, the Democratic People’s Republic of Korea (North Korea) and Israel—continued to modernise their nuclear arsenals and several deployed new nuclear-armed or nuclear-capable weapon systems in 2023.

From the estimated 12, 121 inventory of warheads across the globe in January, about 9,585 were in military stockpiles for potential use. Of them, around 3,904 warheads were deployed with missiles and aircraft—60 more than in January 2023—and the rest were in central storage. Around 2100 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, but for the first time China is believed to have some warheads on high operational alert.

India, Pakistan and North Korea are all pursuing the capability to deploy multiple warheads on ballistic missiles, something Russia, France, the UK, the USA and—more recently—China already have. This would enable a rapid potential increase in deployed warheads, as well as the possibility for nuclear-armed countries to threaten the destruction of significantly more targets.

Russia and the USA together possess almost 90 per cent of all nuclear weapons. The sizes of their respective military stockpiles (usable warheads) seem to have remained relatively stable in 2023, although Russia is estimated to have deployed around 36 more warheads with operational forces than in January 2023. Transparency regarding nuclear forces has declined in both countries in the wake of Russia’s full-scale invasion of Ukraine in February 2022, and debates around nuclear-sharing arrangements have increased in saliency.

‘China is expanding its nuclear arsenal faster than any other country,’ 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).

‘But in nearly all of the nuclear-armed states there are either plans or a significant push to increase nuclear forces,’ he said.

Although the UK is not thought to have increased its nuclear weapon arsenal in 2023, its warhead stockpile is expected to grow in the future as a result of the British government’s announcement in 2021 that it was raising its warheads limit from 225 to 260. It will no longer publicly disclose its quantities of nuclear weapons, deployed warheads or missiles.

France continued its programmes to develop a third-generation nuclear-powered ballistic missile submarine (SSBN) and a new air-launched cruise missile in 2023, as well as to refurbish and upgrade existing systems.

India slightly expanded its nuclear arsenal in 2023. Both India and Pakistan continued to develop new types of nuclear delivery systems in 2023. While Pakistan remains the main focus of India’s nuclear deterrent, India appears to be placing growing emphasis on longer-range weapons, including those capable of reaching targets throughout China.

North Korea continues to prioritize its military nuclear programme as a central element of its national security strategy. SIPRI estimates that the country has now assembled around 50 warheads and possesses enough fissile material to reach a total of up to 90 warheads, both significant increases over the estimates for January 2023.

While North Korea conducted no nuclear test explosions in 2023, it appears to have carried out its first test of a short-range ballistic missile from a rudimentary silo. It also completed the development of at least two types of land-attack cruise missile (LACM) designed to deliver nuclear weapons.

‘Like several other nuclear-armed states, North Korea is putting new emphasis on developing its arsenal of tactical nuclear weapons,’ said Matt Korda, Associate Researcher with SIPRI’s Weapons of Mass Destruction Programme and Senior Research Fellow for the Nuclear Information Project at the Federation of American Scientists. ‘Accordingly, there is a growing concern that North Korea might use these weapons very early in a conflict.’

Israel, which does not publicly acknowledge possessing nuclear weapons, is also believed to be modernizing their nuclear arsenal and appears to be upgrading its plutonium production reactor site at Dimona.

Nuclear arms control and disarmament diplomacy suffered more major setbacks in 2023. In February 2023 Russia announced that t was suspending its participation in the 2010 Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START)—the last remaining nuclear arms control treaty limiting Russian and US strategic nuclear forces. As a countermeasure, the USA has also suspended sharing and publication of treaty data.