6. World nuclear forces

At the start of 2025, nine states—the United States, Russia, the United Kingdom, France, China, India, Pakistan, the Democratic People’s Republic of Korea (North Korea) and Israel—together possessed approx-imately 12 241 nuclear weapons, of which 9614 were considered to be potentially oper-ationally available. An estimated 3912 of these warheads were deployed with operational forces, including about 2100 that were kept in a state of high oper-ational alert on ballistic missiles.

Overall, the number of nuclear warheads in the world continues to decline, due to the USA and Russia dismantling retired war-heads. However, the number of warheads being dismantled annually appears to be decreasing and it seems likely that the rate at which retired warheads are dismantled will soon be outpaced by the rate at which new warheads enter global stockpiles. Low levels of transparency hinder assessments of the status of states’ nuclear arsenals.

Global nuclear weapon inventories, January 2025

Nuclear weapon modernization trends

All the nine nuclear-armed states continued to strengthen their nuclear arsenals in 2024 and some deployed new nuclear-armed or nuclear-capable weapon systems during the year. The USA and Russia together possess almost 90 per cent of all nuclear warheads, and both have extensive programmes under way to modernize and replace their nuclear warheads as well as their delivery systems and nuclear weapon production facilities. China is in the middle of a significant modernization and expansion of its nuclear arsenal, which is estimated to have increased from 500 to up to 600 warheads during the year. The nuclear arsenals of the other nuclear-armed states are smaller, but all are either developing or deploying new weapon systems or have announced their intention to do so.

Russia, China, India, Pakistan and North Korea deploy dual-capable missiles and all are believed to be modernizing these capabilities. Up until the mid 2000s, only France, Russia, the UK and the USA deployed missiles with multiple warheads. Since then, China has developed two missiles to carry multiple warheads, while India, Pakistan and North Korea are all currently pursuing this capability. The USA, Russia, the UK and France were early adopters of sea-based nuclear weapons, but in recent years these have been proliferating, especially in the four nuclear-armed states in the Indo-Pacific.

Nuclear doctrines and nuclear sharing

In November 2024 Russia updated its official nuclear weapons doctrine, which appeared to expand the range of contingencies under which Russia could use nuclear weapons. Both Russia and Belarus continued to make claims in 2024 that Russia had deployed nuclear weapons on Belarusian territory, although there was no conclusive evidence of this deployment.

Extended nuclear deterrence has been a key component of the North Atlantic Treaty Organization’s collective security arrangements since the alliance’s inception. Discussions about the future of these arrangements, largely triggered by Russia’s full-scale invasion of Ukraine in 2022, continued in 2024. In early 2025 the USA confirmed that it had replaced its nuclear gravity bombs stationed at military bases outside the USA with upgraded versions.