Expiration of New START Treaty Marks New Era of Nuclear Uncertainty

The New Strategic Arms Reduction Treaty (New START), the last remaining nuclear arms control agreement between the United States and Russia, expired on February 5, 2026. This development has raised concerns about the potential for an unconstrained nuclear arms race between the two nations, which together hold approximately 90% of the world's nuclear weapons.

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Signed on April 8, 2010, by President Barack Obama and Russian President Dmitry Medvedev, New START limited each country to 1,550 deployed nuclear warheads and 700 delivery systems, including intercontinental ballistic missiles and bombers. The treaty was initially set to expire in 2021 but was extended for five additional years. However, in February 2023, Russia suspended its participation, citing security concerns amid rising tensions due to the ongoing conflict in Ukraine.

As US-Russia nuclear arms treaty expires, fears of new arms race rise

President Donald Trump has expressed a desire to negotiate a new nuclear arms treaty that includes China, arguing that any future agreement must address the growing Chinese nuclear arsenal. Secretary of State Marco Rubio has echoed this sentiment, stating that true arms control in the 21st century cannot exclude China. Conversely, Russian President Vladimir Putin had previously offered to extend New START's limits for an additional year, a proposal that went unanswered by the U.S.

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In a statement marking the treaty's expiration, UN Secretary-General Antonio Guterres emphasized the gravity of the situation, noting that "for the first time in more than half a century, we face a world without any binding limits on the strategic nuclear arsenals" of the U.S. and Russia. The Kremlin expressed regret over the treaty's expiration, with spokesperson Dmitry Peskov stating that Russia remains open to dialogue if the U.S. responds constructively.

Russia says regrets nuclear treaty expiration, Trump wants new pact

Critics, including arms control advocates, warn that the end of New START could lead to a renewed arms race. Daryl Kimball, executive director of the Arms Control Association, cautioned that without a new agreement, the U.S. and Russia might increase their nuclear arsenals, prompting China to accelerate its own nuclear buildup. U.S. lawmakers, including Senators Elizabeth Warren and Ed Markey, have called for urgent action to replace New START to prevent escalating tensions.

Russia says regrets nuclear treaty expiration, Trump wants new pact

While Russia has indicated a willingness to continue observing New START's limits informally, the U.S. has not committed to this approach. Reports suggest that negotiations were ongoing in Abu Dhabi just before the treaty's expiration, but no formal agreement was reached. The lack of clarity surrounding future arms control negotiations raises concerns about the potential for miscalculation and increased nuclear risks.

US, Russia close in on deal to continue New START nuclear arms treaty, Axios reports

The expiration of New START presents an opportunity for both the U.S. and Russia to reimagine arms control in a changing security environment. Guterres urged both nations to return to negotiations promptly to establish a successor framework that restores verifiable limits and enhances global security. As geopolitical tensions rise, the urgency for renewed arms control efforts is more critical than ever.

UN chief warns of ‘grave moment’ as final US-Russia nuclear arms treaty expires