SIPRI Warns of New Nuclear Arms Race as China’s Arsenal Hits 600

The world is quietly slipping into a dangerous new phase of nuclear competition. According to the latest Stockholm International Peace Research Institute (SIPRI) Yearbook 2025, China has rapidly increased its nuclear weapons stockpile, raising serious concerns among global security experts.

As of January 2025, China now possesses at least 600 nuclear warheads, adding about 100 warheads each year in 2023 and 2024. This makes China the fastest-growing nuclear power in the world today. What’s more alarming is that this expansion is happening at a time when the long-standing trend of reducing nuclear weapons since the end of the Cold War seems to be reversing.

SIPRI’s report highlights that all nine nuclear-armed countries — the United States, Russia, China, the United Kingdom, France, India, Pakistan, North Korea, and Israel — are actively modernising their arsenals. This involves upgrading older weapons, deploying new missile systems, and developing advanced technologies to improve their nuclear capabilities.

A Changing Global Nuclear Landscape

Out of an estimated 12,241 nuclear warheads worldwide by early 2025, about 9,614 are currently held in military stockpiles, ready for potential use. Of these, 3,912 are already deployed on missiles or aircraft. Even more concerning, nearly 2,100 of them are on high operational alert, mostly belonging to the United States and Russia.

Russia and the United States still control around 90% of the world’s nuclear weapons, with Russia holding 5,459 warheads and the US about 5,177. However, China’s rapid build-up is changing the balance. The country has completed or is close to finishing around 350 new intercontinental ballistic missile (ICBM) silos in its northern deserts and eastern mountains — a clear sign of long-term strategic planning.

If this growth continues, experts believe China could match the number of ICBMs held by the US or Russia by the end of this decade. At the current pace, China may possess around 1,000 warheads within 7–8 years, and possibly 1,500 by 2035. Even then, it would still have about one-third of the stockpiles maintained by the two major nuclear superpowers — but its rise could trigger intensified competition.

Other Nations Modernising Too

Other nuclear-armed countries are also updating their arsenals:

• India’s stockpile has grown to about 180 warheads, and the country is developing new missile systems for land, air, and sea.

• Pakistan maintains around 170 warheads, with new delivery systems in development.

• North Korea has about 50 warheads, but enough fissile material to possibly double that number soon.

• The United Kingdom and France continue to modernise and maintain their arsenals, with possible expansions in the future.

• Israel’s nuclear stockpile remains stable at around 90 warheads, although details about its program are officially unconfirmed.

Growing Risks in a New Technological Era

SIPRI’s experts have raised alarms about the growing risks of nuclear war or accidental conflict, made worse by the rise of emerging technologies. The rapid development of artificial intelligence, cyber warfare, missile defence systems, and quantum computing is changing the nature of nuclear deterrence. These advancements increase the chances of misjudgment or miscalculation, especially in a high-tension global environment.

Adding to this uncertainty is the weakening of arms control agreements. The New START treaty, the last major nuclear weapons agreement between the US and Russia, is set to expire in 2026, with no replacement deal currently in sight.

A Return to Cold War Tensions

According to SIPRI Director Dan Smith, the world is now entering an era reminiscent of Cold War rivalries — but with even greater complexity due to advanced technology and more nuclear players. The steady reduction in nuclear weapons, a positive trend that had continued for decades after the Cold War, is now giving way to a period of modernisation, expansion, and heightened nuclear risks.

At the heart of this shifting nuclear landscape is China’s rapid and determined build-up, which is reshaping the balance of power and forcing other nations to respond. If these trends continue unchecked, the world could see the dawn of a new and dangerous nuclear arms race.