The last major nuclear arms control treaty between the United States and Russia expired at midnight GMT on Wednesday, February 5, 2026, marking what United Nations Secretary-General Antonio Guterres called a “grave moment for international peace and security.”
UN Chief Urges Immediate Return to Negotiations
Antonio Guterres issued a stark warning, urging Washington and Moscow to “agree” swiftly on a new disarmament framework. He emphasized that the lapse of the treaty comes at the worst possible time, with the risk of nuclear weapon use at its highest level in decades.
“This dissolution of decades of gains could not come at a worse time,” Guterres stated. “I urge both states to return to the negotiating table without delay and agree on a new framework.”
End of an Era in Strategic Arms Control
The New START treaty, signed in 2010, was the final pillar of Cold War-era arms control architecture. It limited each party to 800 deployed launchers and heavy bombers and 1,550 deployed strategic offensive warheads, featuring a crucial verification mechanism.
Its expiration creates an unprecedented situation. “For the first time in more than half a century, we are facing a world without any binding limits on the strategic nuclear arsenals of the Russian Federation and the United States of America,” the UN chief lamented.
Broader Context of Disarmament Breakdown
The treaty’s end follows years of escalating tensions and the suspension of on-site inspections in 2023 following Russia’s full-scale invasion of Ukraine. This collapse is part of a broader unraveling of nuclear agreements.
- The United States withdrew from the Intermediate-Range Nuclear Forces (INF) Treaty in 2019.
- Russia and the US collectively possess over 80% of the world’s nuclear warheads.
- The verification regime that provided transparency has been dismantled.
The international community now watches anxiously as the world’s two largest nuclear powers operate without any formal constraints on their strategic arsenals for the first time since the 1970s.
