Last US-Russia nuclear pact expires, fueling fears of a new arms race

WASHINGTON (AP) — The last remaining nuclear arms control treaty between the United States and Russia expired Thursday, ending a decade-long framework that limited the world’s two largest nuclear arsenals.

The New START treaty, signed in 2010, capped both nations at 1,550 deployed strategic nuclear warheads. President Trump allowed the agreement to lapse, stating he intends to pursue a new deal that includes China.

Secretary of State Marco Rubio declared a deal "impossible" without Beijing’s participation, citing China's rapidly expanding military capabilities. The Pentagon estimates China will possess more than 1,000 nuclear weapons by 2035.

Beijing has refused to join negotiations, arguing its stockpile remains significantly smaller than those of Washington or Moscow.

The Kremlin expressed regret over the treaty’s expiration. Following the lapse, the Russian Foreign Ministry announced that the parties are no longer bound by the agreement's obligations.

While Russia suspended inspections during the war in Ukraine, officials noted the country had not significantly violated the treaty’s deployment limits.

Arms control experts warned that the absence of a treaty could trigger a new global arms race and heighten the risk of nuclear proliferation.

The expiration of the New START treaty marks the definitive end of the era of bilateral U.S.-Russia arms control, ushering in a more volatile tripolar security landscape defined by the strategic rise of China. The Trump administration’s decision to allow the treaty to lapse represents a high-stakes gambit aimed at forcing Beijing into a future multilateral regulatory framework. From Washington’s perspective, a status quo that constrains Moscow’s arsenal while ignoring Beijing’s rapid nuclear expansion is no longer strategically viable.

China’s rejection of these overtures was predictable. Given that its inventory remains significantly smaller than those of the two traditional nuclear superpowers, Beijing views participation in a trilateral accord on U.S. terms as a calculated attempt to stifle its strategic deterrence and contain its geopolitical ascent. Russia, meanwhile, occupies a paradoxically advantageous position. While Moscow has publicly lamented the treaty’s demise, the collapse of New START effectively grants the Kremlin a "free hand" to expand its capabilities, citing the necessity of counterbalancing the combined pressures of both the U.S. and China.

This shift has created a "trilateral security dilemma": Washington now faces the reality that it cannot simultaneously constrain Moscow and Beijing without triggering reciprocal escalations from at least one party. The projected outcome is a costly, three-way arms race that will likely force the United States to accelerate the modernization of its aging nuclear triad. As former officials have warned, this instability not only strains defense budgets but also heightens the risk of global nuclear proliferation, as other middle powers may feel compelled to develop their own deterrents in response to a more fractured international security order.