Obama Warns of Nuclear Arms Race If U.S.-Russia Treaty Expires

The former president says Congress must act before the New START treaty ends to avoid "pointlessly wiping out decades of diplomacy."

Published on Feb. 3, 2026

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Former U.S. President Barack Obama has warned that the impending expiration of the New START treaty between the U.S. and Russia could spark another superpower arms race. Obama wrote on social media that Congress should act before the treaty, which he signed in 2010, expires on Thursday, as its expiry would "pointlessly wipe out decades of diplomacy, and could spark another arms race that makes the world less safe."

Why it matters

The New START treaty, signed by Obama and then-Russian President Dmitry Medvedev in 2010, limits strategic nuclear weapons to 1,550 each. It can be extended only once, which happened in 2021 under then-President Joe Biden. However, Russian President Vladimir Putin has since suspended Moscow's participation due to Washington's support for Ukraine. Obama's message is the latest warning about the consequences for nuclear proliferation if the deal expires.

The details

The expiry of New START, which required regular data exchanges and notifications of the number and status of weapons, leaves a void - raising concerns over a breakdown of nuclear restraint between Russia and the United States, which together possess 87 percent of the world's nuclear weapons. Matt Korda, from the Nuclear Information Project at the Federation of American Scientists, told Newsweek that Russia's nuclear modernization was facing significant challenges, and that its flagship programs to produce the next generation of nuclear weapons are over budget and behind schedule.

  • The New START treaty expires on Thursday, February 5, 2026.
  • Obama signed the New START treaty in 2010.
  • The treaty was extended once in 2021 under then-President Joe Biden.

The players

Barack Obama

The former President of the United States who signed the New START treaty with Russia in 2010.

Vladimir Putin

The current President of Russia who has suspended Moscow's participation in the New START treaty due to Washington's support for Ukraine.

Dmitry Medvedev

The former President of Russia who signed the New START treaty with Obama in 2010.

Joe Biden

The former President of the United States who extended the New START treaty in 2021.

Matt Korda

The associate director of the Nuclear Information Project at the Federation of American Scientists.

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What they’re saying

“If Congress doesn't act, the last nuclear arms control treaty between the U.S. and Russia will expire. It would pointlessly wipe out decades of diplomacy, and could spark another arms race that makes the world less safe.”

— Barack Obama, Former U.S. President (X)

“New START was the last guardrail limiting the most destructive weapons ever built. Its collapse leaves the world more dangerous and less predictable.”

— Tilman Ruff, Co-founder of the International Campaign to Abolish Nuclear Weapons (Newsweek)

“Without any kind of bilateral strategic arms control between these two nuclear superpowers, we're entering terrain that we have not been in several decades.”

— Matt Korda, Associate Director of the Nuclear Information Project (Newsweek)

What’s next

The White House has not publicly responded to Russia's call for a one-year informal agreement to stick to weapons limits, adding to concerns about what the expiry of the New START deal would mean for nuclear proliferation after February 5.

The takeaway

The expiration of the New START treaty between the U.S. and Russia could have dire consequences for global nuclear nonproliferation efforts, potentially sparking a new arms race between the two nuclear superpowers if Congress does not act to extend or replace the agreement.