Nuclear & Arms Control — 2026-05-10

New START Treaty Expires Ending Last Nuclear Arms Limitation Accord

New START expired on February 5 without a U.S. response to Russia's proposal to continue informally abiding by its central limits, leaving both sides without legally binding curbs on strategic weapons deployments. Trump posted the same day that Washington would pursue a "new, improved, and modernized" agreement; Russian Foreign Minister Lavrov told parliament on February 11 that Moscow would observe a conditional moratorium on treaty limits only as long as Washington does the same. U.S. Undersecretary DiNanno stated in Geneva on February 6 that Washington's priorities for a successor agreement include all Russian nuclear weapons and China's expanding stockpiles, and that the United States retains "non-deployed nuclear capacity" deployable if directed by the president. CFR reporting notes that Trump's One Big Beautiful Bill Act designates $62 million to reopen previously closed missile tubes on Ohio-class submarines.

Analysis
New START's expiration strips both intelligence communities of the only mechanism giving reliable confidence in adversary force posture. Washington's multilateral scope demand and Beijing's publicly stated refusal, reiterated February 6 per Arms Control Association and CFR and corroborated by diplomatic and former-official sources, make a formal successor unlikely by February 2027. Russia's moratorium is unilaterally conditioned on U.S. compliance, giving Moscow a trigger to abandon even informal limits. Congress has moved to concrete upload: $62 million appropriated to reopen Ohio-class missile tubes. Moscow's alarm may primarily be diplomatic framing casting Washington as destabilizing rather than genuine concern about a competition Russia cannot sustain economically. Without verification, force estimates widen into ranges, accelerating the action-reaction cycle.

1 sources

In 2026, a Growing Risk of Nuclear Proliferation - Arms Control Association