While Israel bombs Iran over nukes, nuclear-armed nations, including the U.S., are accelerating arsenal upgrades, warns study

While Israel is pounding Iran with bombs, alleging attempts to make nuclear weapons, nearly all the nine nuclear-armed countries, including India and Pakistan, continued intensive nuclear modernisation programmes in 2024, upgrading existing weapons and adding newer versions, says the Stockholm International Peace Research Institute (SIPRI).

Russia and the U.S. together possess around 90% of all nuclear weapons. The U.S. has an inventory of 5177 warheads and 5459 is with Russia. China has 500, followed by France with 290 and the UK with 225. India has 180, closely followed by Pakistan with 170. Israel has 90 and North Korea 50.

SIPRI, an authority on global arms trade, pointed out that the U.S., Russia, the United Kingdom, France, China, India, Pakistan, the Democratic People’s Republic of Korea (North Korea) and Israel have a total global inventory of an estimated 12,241 warheads, as of January 2025.

Of this, about 9614 were in military stockpiles for potential use. Since the end of the Cold War, the gradual dismantlement of retired warheads by Russia and the U.S. 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, says SIPRI.

China’s nuclear arsenal is growing faster than that of 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 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 U.S. by the turn of the decade. Yet, even if China reaches the maximum projected number of 1500 warheads by 2035, that will still amount to only about one-third of each of the current Russian and U.S. nuclear stockpiles.

Both Russian and U.S. deployments of nuclear weapons will likely rise in the years ahead, predicts SIPRI. The Russian increase would mainly happen as a result of modernising the remaining strategic forces to carry more warheads on each missile and reloading some silos that were emptied in the past. The U.S. increase could happen as a result of more warheads being deployed to existing launchers, empty launchers being reactivated, and new non-strategic nuclear weapons being added to the arsenal. Nuclear advocates in the U.S. are pushing for these steps as a reaction to China’s new nuclear deployments.

SPIRI says India is believed to have once again slightly expanded its nuclear arsenal in 2024 and continued to develop new types of nuclear delivery system. 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.

SIPRI also warned that revitalised national debates in East Asia, Europe and the Middle East about nuclear status and strategy suggest there is some potential for more states to develop their own nuclear weapons.