Global watchdog flags dangerous shift as nuclear states ramp up arsenals amid waning arms control frameworks.
The world is facing the sobering prospect of a new nuclear arms race, with all nine nuclear-armed nations expanding and modernising their arsenals at a time of increasing geopolitical instability, according to the Stockholm International Peace Research Institute (SIPRI).
In its 2025 Yearbook, the respected international security think tank warned that nuclear weapons, long thought of as a Cold War relic, are becoming a renewed threat to global peace. The report highlights a dramatic reversal of post-Cold War disarmament trends, with stockpiles being upgraded in potency, delivery and accuracy — ushering in what SIPRI calls a “step change” in nuclear strategy.
Dan Smith, Director of SIPRI, called the developments “deeply troubling,” adding: “We’re not seeing a few states tinkering on the margins. It’s a full-scale modernisation across the board — from the long-established nuclear powers to more recent entrants like India and Pakistan, and even North Korea.”
The report highlights a dramatic reversal of post-Cold War disarmament trends, with stockpiles being upgraded in potency, delivery and accuracy — ushering in what SIPRI calls a “step change” in nuclear strategy.
Growing arsenals, shrinking agreements
The Yearbook’s starkest finding is that while the overall number of nuclear warheads globally has marginally declined to 12,241, the number of warheads ready for potential use has increased. As of January 2025, around 9,614 warheads were in military stockpiles, with 3,912 deployed on missiles and aircraft — 2,100 of them kept on high operational alert, predominantly by the US and Russia.
The alarming developments are set against the backdrop of failing arms control mechanisms. With long-standing treaties like the INF Treaty and New START either defunct or under strain, opportunities for multilateral disarmament have dwindled.
“The era of nuclear reductions is over,” said Hans M Kristensen, a senior fellow at SIPRI and director at the Federation of American Scientists. “Instead, we are witnessing rising stockpiles, the resurgence of nuclear rhetoric, and an abandonment of transparency.”
China’s rapid expansion
Perhaps the most striking revelation is China’s nuclear acceleration. According to SIPRI, Beijing added 100 new warheads in the past year alone, bringing its total to around 600. Construction has been completed or is near completion on 350 new intercontinental ballistic missile (ICBM) silos, with projections suggesting China could reach 1,000 warheads by 2032 — and as many as 1,500 by 2035.
Though still trailing behind Russia and the US, both of which hold over 5,000 warheads each, China’s pace of development is unmatched. SIPRI also reports signs that Beijing may now be keeping some of its nuclear warheads mated to missiles during peacetime — a potentially game-changing shift in posture.
South Asia’s steady build-up
India and Pakistan also feature prominently in the Yearbook, with both countries continuing to expand their arsenals. India’s rollout of canisterised missile systems, which could eventually allow the peacetime deployment of warheads, marks a significant doctrinal shift.
Pakistan, meanwhile, is believed to be increasing its stockpile of fissile material and refining its delivery mechanisms. SIPRI’s findings suggest Islamabad’s arsenal could grow significantly in the coming decade.
North Korea and Israel
North Korea, often seen as a nuclear wild card, is estimated to possess 50 nuclear warheads, with fissile material sufficient for 40 more. Though not increasing its arsenal in 2024, Pyongyang continues to develop its weapons capabilities. Israel, which has never officially acknowledged its nuclear arsenal, is estimated to have 90 warheads.
SIPRI’s report also explores the role of emerging technologies in redefining the nuclear landscape. Innovations in artificial intelligence, quantum computing, missile defence, and cyber warfare could potentially undermine traditional deterrence strategies and introduce new instabilities.
Dan Smith warned, “Quantum technologies deployed in oceans, advances in missile defence and AI-guided systems are making previously stable nuclear doctrines more fragile. These developments are outpacing the frameworks designed to control them.”
The report also touches on geopolitical shifts. The ongoing wars in Ukraine and Gaza, deepening East-West divisions, and the re-election of Donald Trump have all contributed to global insecurity. In particular, SIPRI notes rising concerns in Europe and Asia about the future reliability of the US as a security partner.
While the tone of SIPRI’s Yearbook is grim, its authors say that reversing this dangerous momentum is not impossible — but it requires immediate, coordinated global effort.
“Without a serious recommitment to arms control, non-proliferation, and strategic dialogue,” warned Kristensen, “the world could very well sleepwalk into a new nuclear era — one potentially more dangerous than the last.”
