Global nuclear risks rise despite slight reduction in warheads, Stockholm institute warns

The world’s nuclear-armed states are modernizing arsenals and reducing transparency, heightening the risk of escalation even as the total number of warheads declines, according to a report published Monday by the Stockholm International Peace Research Institute (Sipri).

Global stockpiles fell from 12,241 warheads in 2025 to 12,187 this year, the annual assessment found. Yet Sipri director Karim Haggag cautioned that “the danger surrounding nuclear weapons has increased” due to worsening geopolitical tensions and growing conflicts between nuclear powers.

Several nations are upgrading their arsenals with new submarine-launched missiles and hypersonic systems, while France has announced plans to expand its stockpile while ceasing to disclose its size. Haggag warned that while not yet underway, “we could be heading toward a new nuclear arms race.”

The collapse of key agreements has further eroded stability. The US-Russia New START treaty expired in February without renewal, and a third consecutive review conference for the Nuclear Non-Proliferation Treaty failed to reach consensus. Meanwhile, the number of deployed warheads has risen, despite the overall reduction in total inventories.

Sipri highlighted China’s arsenal as the fastest-growing, alongside ongoing modernization programs in the US and Russia. India and Pakistan are also expanding their capabilities.

“This should concern us all,” Haggag said, urging collective action to restore “strong limitations on nuclear weapons” and reduce reliance on them for security.