As geopolitical ties worsen, the role of nuclear weapons increases the new SIPRI Yearbook is now available.

Global nuclear arsenals are getting stronger The Democratic People's Republic of Korea (North Korea), the United States, Russia, the United Kingdom, France, China, India, Pakistan, and Israel are the nine nuclear-armed states. All nine of these states have been updating their nuclear arsenals, and several of them will be deploying new nuclear-armed or nuclear-capable weapon systems in 2023.About 9585 of the estimated 12,121 warheads in the world's inventory as of January 2024 were held in military stocks for possible deployment (see the table below). Sixty-nine of those warheads were in central storage, leaving an estimated 3904 warheads that were used with missiles and aircraft in January 2023. On ballistic missiles, about 2100 of the deployed warheads were maintained in a high operational alert status. These warheads belonged to the USA or Russia almost entirely, although China is thought to have several on high operational alert for the first time."Unfortunately, we continue to see year-on-year increases in the number of operational nuclear warheads, even as the global total of nuclear warheads continues to fall as cold war-era weapons are gradually dismantled," SIPRI Director Dan Smith said.

"This trend is very concerning as it seems likely to continue and probably accelerate in the coming years."The ability to mount multiple warheads on ballistic missiles, which is already possessed by Russia, France, the UK, the USA, and—more recently—China, is something that India, Pakistan, and North Korea are all vying for. This would make it possible for the number of warheads in use to rise quickly and for nations with nuclear weapons to threaten the destruction of a great deal more targets.Together, the United States and Russia are in possession of about 90% of all nuclear weapons. Although Russia is reported to have deployed about 36 more warheads with operational troops than in January 2023, the sizes of their respective military stockpiles (i.e., serviceable warheads) appear to have remained largely steady in 2023. Following Russia's full-scale invasion of Ukraine in February 2022, both countries have seen a fall in nuclear force transparency, while discussions surrounding nuclear-sharing agreements have gained more importance.