The Last U.S.–Russia Nuclear Pact Expires, Prompting Fears of a New Arms Race

The New START nuclear arms control treaty between the United States and Russia officially expired, ending binding limits on their strategic nuclear arsenals for the first time in more than 50 years and raising global concerns of a renewed arms race and heightened nuclear risks.

By David Thompson – News Reporter

Last Updated: Feb. 4, 2026

New START Treaty Expires After 15 Years of Limits

On February 5, 2026, the New Strategic Arms Reduction Treaty (New START) — the last remaining nuclear arms control agreement between the United States and Russia — officially expired, removing caps that had limited each side to 1,550 deployed nuclear warheads and 700 launch systems. The pact, signed in 2010 by Presidents Barack Obama and Dmitry Medvedev and extended once in 2021, had served for more than a decade as the cornerstone of U.S.–Russia nuclear restraint and transparency. :contentReference[oaicite:1]{index=1}

Limits Vanish Just as Inspections Lapsed

Although the treaty’s verification mechanisms, including on‑site inspections, had largely fallen into disuse due to the COVID‑19 pandemic and Moscow’s suspension of participation in 2023, its formal limits still provided a framework for strategic stability. With the expiration, both nations are no longer legally bound to adhere to these ceilings, and there is no immediate successor agreement in place, leaving the world’s two largest nuclear arsenals unconstrained for the first time in decades. :contentReference[oaicite:2]{index=2}

Global Leaders Warn of Heightened Risk

International voices have sounded alarms over the treaty’s lapse. U.N. Secretary‑General António Guterres described the moment as a “grave” threat to global peace and emphasized the urgent need for renewed negotiation to reduce nuclear threats. Experts and arms control advocates warn that without concrete restraints, both countries could expand their stockpiles and reduce transparency, increasing risks of miscalculation and signaling a broader erosion of post‑Cold War arms control architecture. :contentReference[oaicite:3]{index=3}

Russia and U.S. Offer Competing Responses

Russian officials have stated that Moscow remains open to diplomacy but will counter any new threats following the treaty’s expiration, framing the decision as balanced and based on security analysis. Russian President Vladimir Putin previously offered to continue observing the pact’s limits if the United States reciprocated, but U.S. President Donald Trump declined to extend the treaty without broader agreements involving China — a proposal Beijing has rejected. These dynamics underscore the complex geopolitics surrounding nuclear arms control in an era of strained relations. :contentReference[oaicite:4]{index=4}

Fears of a New Arms Race and Broader Implications

With the New START treaty expired and no replacement framework agreed, analysts warn of the potential for an unconstrained nuclear arms buildup not only between the U.S. and Russia but also involving other nuclear powers like China, whose arsenal is rapidly expanding. Critics say the end of this last major bilateral pact could undermine global non‑proliferation norms, weaken trust, and make nuclear deterrence dynamics more unpredictable, reviving Cold War‑era fears of a new arms race. :contentReference[oaicite:5]{index=5}