Last U.S.-Russia Nuclear Arms Treaty Expires With No Successor in Place

New START, the last treaty limiting American and Russian nuclear weapons, expired on Thursday, leaving the world’s two largest arsenals without binding limits for the first time in more than half a century, according to Swissinfo and Al Jazeera. No successor agreement is in place.

The treaty was signed in 2010 and took effect in 2011. It capped each country at 1,550 deployed strategic warheads, 700 deployed missiles and bombers, and 800 launchers, according to Swissinfo and the Arms Control Association. In 2021 the two sides agreed to extend it by five years, to Feb. 5, 2026, Al Jazeera and the association reported.

Verification had already eroded. The Arms Control Association said Russia announced in February 2023 that it was suspending implementation of the treaty, and Swissinfo reported that Moscow suspended parts of it but kept respecting the numerical ceilings. Fox News, in a later report, said Russia also stopped allowing on-site inspections of its nuclear facilities and halted required data exchanges that year.

Moscow proposed in September 2025 to keep observing the central limits for another year, according to Swissinfo and the Arms Control Association. The association said Washington did not respond, and Al Jazeera reported that Russia’s Foreign Ministry made the same complaint in the days before the expiry.

Trump has played down the lapse. “If it expires, it expires. We’ll do a better agreement,” he told The New York Times in January, as quoted by Al Jazeera and Swissinfo. The administration wants China included in any new framework, Al Jazeera and Fox News reported. Beijing has rejected joining, noting that its arsenal is about a tenth the size of the American and Russian stockpiles, Swissinfo said, and Fox News reported that experts doubt it will accept binding limits while its arsenal is growing.

The arsenals are large. Fox News, citing expert estimates, put Russia and the United States at about 4,000 warheads in total, with China projected to reach about 1,000 by 2030. Al Jazeera, citing January 2025 figures, put Russia at about 4,309 warheads and the United States at about 3,700, with China at about 600, France 290 and Britain 225.

Swissinfo and Al Jazeera both reported concern that the end of the limits could feed a new arms race, and Al Jazeera added that both sides will be free to increase missile numbers. The Bulletin of the Atomic Scientists has moved its symbolic Doomsday Clock to 85 seconds to midnight, Swissinfo and Fox News noted.