The decades-long decline in global nuclear weapons stockpiles has ended, and the number of warheads worldwide will likely start climbing in the near future, according to a new study by the Stockholm International Peace Research Institute (SIPRI).
The United States and Russia hold the vast majority of the world’s nuclear warheads – around 90%, according to SIPRI’s estimates. Of the total global stockpile of around 12,241, Russia owns 5,459 and the United States about 5,177.
Experts at SIPRI expect that both countries are beginning to grow their overall arsenals again after of progress in decommissioning ageing nukes built during the Cold War. “The pace of dismantlement is slowing, while the deployment of new nuclear weapons is accelerating,” the report states.
Western Europe’s two nuclear powers, the United Kingdom and France, are also looking to modernise and upgrade their more modest arsenals. Risks of further nuclear proliferation in Europe have also risen, as countries react to the threat of Russian aggression and the possibility that the US might pull back on security guarantees for allies on the continent.
“While new nuclear states aren’t going to appear overnight, it is clear that many countries are increasingly thinking about nuclear weapons as a silver bullet for their national security,” Matt Korda, an associate senior researcher at SIPRI’s Weapons of Mass Destruction Programme, told Euractiv.
Renewed nuclear focus in London and Paris
The UK has plans to grow their current arsenal of 225 warheads to 260, although SIPRI did not register a change in 2024. Amid higher NATO military spending, the UK has announced plans to invest £15 billion to expand and advance its own sovereign nuclear capacity in parallel to US warheads.
London backed out of previous commitments to reduce its stockpile in 2021, citing a change in the security environment, and the UK’s recent strategic defence review urged greater participation in NATO nuclear deterrence.
The UK also plans to build more submarines as part of an expansion of the Royal Navy. Currently, the UK’s only nuclear delivery method is via its submarine fleet, althogh the strategic review also recommended acquiring a variant of the F-35 jet that could carry nuclear weapons.
SIPRI estimates that France’s stockpiles, meanwhile, have remained stable at 290 warheads. But France has also been investing in modernising and upgrading its nuclear weapons. French President Emmanuel Macron has opened a discussion over whether the EU’s only nuclear arsenal could play a broader role in defending the continent.
Debate over whether the UK and France could extend their nuclear umbrellas to shield their European allies have intensified this year after Trump’s return to the White House. Even the prospect of an EU nuclear programme was raised in the run-up to the European elections in 2024.
“It remains unclear, though, whether stockpiles would need to be increased to accommodate these changes,” said SIPRI’s Korda.
Arsenals growing everywhere
Other powers elsewhere in the world are actively pushing for more nukes as well, according to the SIPRI report.
China has the fastest-growing arsenal in the world, adding about 100 per year since 2023, growing to an estimated 600 warheads, according to SIPRI. India, which is entangled in a long-standing conflict with Pakistan that’s recently escalated, is believed to have expanded their arsenal slightly in 2024 to about 180 warheads – and the Swedish research institute expects Pakistan’s 170 warhead arsenal to grow substantially in the next decade.
The report also estimated Israel’s nuclear arsenal – which the country officially does not acknowledge – at 90 warheads as of January 2025. North Korea, meanwhile, may possess roughly 50 warheads and has enough nuclear material to expand to 90, according to estimates of SIPRI.
(bts)
