AP
Moscow, Updated Feb. 5, 2026 — The final remaining nuclear arms agreement between the United States and Russia expired on Thursday, removing formal limits on the world’s two largest atomic arsenals for the first time in more than 50 years. Analysts warned the lapse of New START could open the door to an unconstrained nuclear arms competition.
Russian President Vladimir Putin had said last year he would be willing to keep observing the treaty’s limits for an additional year if the United States did the same. U.S. President Donald Trump, however, did not agree to extend the pact.
Kremlin aide Yuri Ushakov said Putin discussed the treaty’s expiration with Chinese leader Xi Jinping and that Moscow has received no response from Washington to its extension proposal. Ushakov added that Russia “will act in a balanced and responsible manner based on thorough analysis of the security situation.”
On Wednesday night, the Russian Foreign Ministry said that under current conditions the treaty’s parties are no longer bound by its obligations or by the mutual declarations it established, and are free to choose their next steps.
New START, signed in 2010 by then-U.S. President Barack Obama and Russian President Dmitry Medvedev, capped each country at no more than 1,550 deployed nuclear warheads on up to 700 deployed missiles and bombers. The agreement, originally due to expire in 2021, had been extended for five years.
The accord included on-site inspections to verify compliance, but those inspections were suspended in 2020 because of the COVID-19 pandemic and did not resume. In February 2023, Putin announced a suspension of Russia’s participation, citing concerns about U.S. inspections of Russian nuclear sites while Washington and NATO publicly discussed plans to defeat Moscow in Ukraine. At that time, the Kremlin said it was not withdrawing from the treaty and intended to respect its limits.
In September, Putin offered to adhere to New START limits for one more year to allow talks toward a successor agreement, warning that letting the treaty lapse would be destabilizing and might encourage nuclear proliferation.
New START was the latest in a series of U.S.-Russian arms-reduction accords; many earlier agreements have also expired over the years, raising questions about the future of formal nuclear restraints between the two powers.
