The last remaining U.S.-Russian nuclear arms pact, the New START Treaty, is due to lapse Thursday, ending constraints that have been in place since the pact’s 2010 signing and raising fears that uncertainty could accelerate nuclear competition. Russian President Vladimir Putin said Russia is prepared to keep observing the treaty’s limits for an additional year if Washington follows suit, but President Donald Trump has offered no commitment to extension. The expiration comes as U.S. and Russian leaders have also been weighing broader strategic issues, including the role of China in any future arms-control talks.
The treaty’s scheduled end would remove limits on the two largest atomic arsenals for the first time in more than a half-century, a prospect that arms-control advocates say could set the stage for an unconstrained arms race. Kingston Reif of the RAND Corporation, speaking during an online discussion, warned that without the predictability provided by the treaty, each side could be incentivized to plan for the worst or increase deployed arsenals, or seek negotiating leverage. Daryl Kimball of the Arms Control Association said the two sides could, with the treaty’s expiration, increase deployed nuclear weapons for the first time in about 35 years, opening the possibility of a three-way arms race involving the United States, Russia and China.
Putin declared readiness to extend New START’s limits for another year if Washington agrees, according to a Kremlin adviser, who also said Putin discussed the pact’s expiration with Chinese leader Xi Jinping and noted that Washington had not responded to a proposed extension. The adviser, Yuri Ushakov, said Russia “will act in a balanced and responsible manner based on thorough analysis of the security situation.” By contrast, a White House official who spoke on condition of anonymity said Trump has been noncommittal about extending the treaty and would make a decision on nuclear arms control “on his own timeline.” The official also said Trump had indicated an interest in involving China in arms-control discussions, while Beijing has balked at restrictions on its smaller but growing nuclear arsenal.
In Washington and among arms-control advocates, the concerns center on predictability and deployment. Kimball told The Associated Press that expiration could encourage the U.S. and Russia to raise the number of nuclear weapons deployed on each side. He added that this could expand into a dangerous three-way competition, with China also increasing its smaller but still deadly nuclear arsenal. Reif similarly warned that the absence of treaty predictability could change incentives in ways that make escalation and leverage-seeking more likely.
New START was signed in 2010 by U.S. President Barack Obama and Russian President Dmitry Medvedev, restricting each side to no more than 1,550 nuclear warheads and no more than 700 missiles and bombers, deployed and ready for use. The treaty was originally set to expire in 2021 but was extended for five more years. Its framework also envisioned sweeping on-site inspections to verify compliance; those inspections stopped in 2020 because of the COVID-19 pandemic and were never resumed.
The Kremlin said in February 2023 that it suspended Moscow’s participation, with the rationale that Russia could not allow U.S. inspections of its nuclear sites at a time when the United States and its NATO allies have said publicly that Moscow’s defeat in Ukraine is their goal. At the same time, the Kremlin emphasized it was not withdrawing from the pact altogether, and it pledged to respect the treaty’s caps on nuclear weapons. In September, Putin offered to abide by New START’s limits for a year to provide time for negotiations on a successor agreement, saying expiration would be destabilizing and could fuel nuclear proliferation.
U.S. negotiator Rose Gottemoeller, a former NATO deputy secretary-general and chief U.S. negotiator for the pact, said extending New START would have served U.S. interests. She told an online discussion last month that “A one-year extension of New START limits would not prejudice any of the vital steps that the United States is taking to respond to the Chinese nuclear buildup.” The dispute over whether to extend the caps is unfolding against a backdrop of prior arms-control breakdowns: earlier pacts such as the 1972 Anti-Ballistic Missile Treaty were terminated, and the Intermediate-range Nuclear Forces Treaty ended in 2019, with both episodes contributing to a narrower environment for strategic limits.
The article also described a wider security agenda and signals from both capitals. Since Russia sent troops into Ukraine in 2022, Putin has repeatedly brandished Russia’s nuclear might, warning Moscow was prepared to use “all means” to protect its security interests, and he signed a revised nuclear doctrine in 2024 that lowered the threshold for nuclear weapons use. Dmitry Medvedev, who signed New START and is now deputy head of Putin’s Security Council, said Russia “will promptly and firmly fend off any new threats to our security,” and he urged that if the sides are not heard, Russia would act proportionately seeking to restore parity.
Vatican leader Pope Leo XIV on Wednesday called for the treaty “not to be abandoned without seeking to ensure its concrete and effective continuation.” Meanwhile, Medvedev specifically referenced Trump’s proposed “Golden Dome” missile defense system among potential destabilizing moves, describing a link between offensive and defensive strategic weapons. Arms-control analysts and advocates said the prospect of U.S. changes, as well as discussion of potential nuclear test resumption, could further raise tensions by undermining global nuclear-risk controls.
Separately, the article noted that in November, U.S. Energy Secretary Chris Wright said any proposed nuclear tests would not include nuclear explosions. Kimball warned that resuming tests would “blow a massive hole in the global system to reduce nuclear risk,” prompting Russia to respond in kind and tempting other countries, including China and India, to follow suit. Kimball said the world was heading toward accelerated strategic competition with more spending and increasingly unstable relations involving the United States, Russia and China on nuclear matters.
__ Associated Press writer Michelle L. Price in Washington contributed.
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