The expiration of the U.S.-Russia New START Treaty: The global nuclear arms control system enters uncharted waters.

On February 5, 2026, as the last legally binding nuclear arms control document—the New Strategic Arms Reduction Treaty—expired at midnight Geneva time, the framework limiting the number of nuclear weapons between Washington and Moscow, which had lasted for over half a century, officially collapsed. This marks the first time since the signing of the Strategic Arms Limitation Treaty (SALT I) in 1972 that the world faces a situation where the two largest nuclear arsenals are not bound by any treaty. United Nations Secretary-General António Guterres described it as a grave moment for international peace and security that day, while analysts see a more complex picture: the old order has ended, new rules are yet to be established, and a strategic game involving the United States, Russia, and China is pushing the global nuclear posture to its most uncertain crossroads since the end of the Cold War.

Technical details and immediate impacts of the treaty's invalidation.

The New Strategic Arms Reduction Treaty (New START) was signed in 2010 by then-U.S. President Barack Obama and Russian President Dmitry Medvedev. Its core provisions set the upper limit for deployed strategic nuclear warheads at 1,550 for each side, and limited deployed delivery vehicles such as intercontinental ballistic missiles, submarine-launched ballistic missiles, and heavy bombers to no more than 700. The treaty was originally set to expire in 2021 but was extended for five years until 2026. Although the treaty remained on paper until the very last moment, its practical effectiveness had long been nominal. In February 2023, Russian President Vladimir Putin unilaterally suspended Russia's participation in the treaty, citing the United States and NATO's open pursuit of Russia's defeat in Ukraine, and specifically halted the on-site inspection mechanism. On-site inspections had not resumed since they were interrupted in 2020 due to the COVID-19 pandemic.

The immediate technical impact of the treaty's expiration is clear: both the United States and Russia are no longer obligated to notify each other of changes in their nuclear forces, inspectors are unable to access each other's key nuclear facilities, and all hard limits on the number of delivery vehicles and warheads vanished overnight. The U.S. Navy has begun technical preparations to reactivate launch tubes on Ohio-class strategic nuclear submarines that were previously prohibited by the treaty. On the Russian side, Kremlin spokesperson Peskov stated on February 6 that Russia is prepared to take decisive military-technical measures in response to potential additional threats to national security, which is widely interpreted as Moscow having given the green light to expand its nuclear arsenal.

However, a comprehensive and unconstrained arms race will not unfold immediately. The production of nuclear weapons is a highly complex, costly process constrained by industrial infrastructure. Matt Korda, Deputy Director of the Nuclear Information Project at the Federation of American Scientists, points out that Russia's current modernization efforts are not progressing smoothly, with its industrial capacity deeply entangled in the Ukrainian battlefield. Significantly accelerating nuclear expansion in the short term does not align with its interests. Similarly, the U.S. nuclear weapons industrial complex faces production bottlenecks. Expert Ankit Panda provides a comparative data point: during the peak of the Cold War in the 1960s, the United States could produce approximately 2,000 plutonium pits (the core component of nuclear warheads) annually, whereas the current goal is to increase annual production capacity to 30 by 2028. Industrial realities impose an invisible buffer on this potential race.

Tripartite Game: Strategic Calculations of the United States, Russia, and China

After the treaty's expiration, diplomatic statements from various parties quickly outlined a strategic map of a three-party power struggle. The United States' position was clearly articulated by Secretary of State Marco Rubio and Undersecretary for Arms Control Thomas Dinanno at the Geneva Disarmament Conference on February 6: any future arms control arrangements must include China. Dinanno bluntly stated that today, China's entire nuclear arsenal has no limits, no transparency, no declarations, and no controls. He further made a significant accusation, claiming that the U.S. government has intelligence indicating that China conducted an underground nuclear explosion test with a yield of several hundred tons on June 22, 2020, and attempted to conceal the test through technical means such as decoupling to evade seismic monitoring networks. The U.S. objective is to promote a new treaty involving the United States, Russia, and China.

Beijing's response was equally swift and firm. China's Ambassador for Disarmament Affairs, Shen Jian, refuted the U.S. allegations in Geneva as a false narrative and baseless accusations, emphasizing that China adheres to its commitment to a moratorium on nuclear testing. He reiterated China's consistent position: at this stage, China will not participate in nuclear disarmament negotiations because its nuclear capabilities are not on the same scale as those of the United States or Russia. According to data from the Stockholm International Peace Research Institute, China's nuclear arsenal is expanding at the fastest rate globally, adding approximately 100 nuclear warheads annually since 2023. The total has increased from over 200 in 2020 to about 600 and may exceed 1,000 by 2030. Beijing's logic is clear—it refuses to accept any restrictions before achieving a strategic balance comparable to that of the United States and Russia.

Moscow plays a more complex role. On one hand, Putin proposed in September 2025 to extend the treaty limits for another year to buy time for negotiations, but this was ignored by the Trump administration. On the other hand, Russia attempts to muddy the waters further. Gennady Gatilov, Russia's ambassador to the Geneva Conference on Disarmament, suggested that if Russia were to participate in any new multilateral negotiations, then the United States' NATO nuclear allies—the United Kingdom and France—must also come to the negotiating table. This demand was immediately rejected by the UK and France. On February 6, the Kremlin stated that Russia and the U.S. had reached a consensus during talks in Abu Dhabi to adopt a responsible stance and initiate negotiations as soon as possible, but Peskov simultaneously denied the possibility of an informal extension of the treaty by both sides. Russia's strategy appears to be: while avoiding separate negotiations with the U.S., which is preoccupied with China-related issues, it aims to drag European nuclear states into a deadlock, thereby securing greater freedom of action and diplomatic leverage for itself.

Regional Security Chain Reaction and Nuclear Proliferation Risks

The expiration of the New START Treaty has implications that extend far beyond the triangular relationship among the United States, Russia, and China. It has shaken the cornerstone of the global nuclear non-proliferation system and sent dangerous signals to other countries and regions. The most immediate concern is the credibility of the nuclear umbrella. President Trump has repeatedly questioned the cost of the United States providing extended deterrence to its allies, referring to them as financial burdens. Such rhetoric, combined with the potential wavering of U.S. nuclear commitments, is causing profound anxiety in Europe and Asia.

In Eastern Europe, discussions within countries like Poland regarding whether to seek the deployment or even possess nuclear weapons autonomously have moved from the fringe to the mainstream. In Northeast Asia, facing North Korea's persistent nuclear and missile threats and the rapid expansion of China's nuclear arsenal, debates within Japan and South Korea over nuclear sharing or developing independent nuclear capabilities are also intensifying. Although the political barriers for these countries to take such a step in the short term remain extremely high, the deteriorating strategic environment is eroding the political and psychological defenses that have suppressed nuclear proliferation for decades.

Another risk stems from the technological domain. The existing arms control treaty system primarily targets traditional intercontinental ballistic missiles and bombers, yet lacks constraints on emerging game-changers. Russia’s high-profile display of the Poseidon nuclear-powered unmanned underwater vehicle and the Burevestnik nuclear-powered cruise missile, China’s tested hypersonic glide vehicle capable of carrying nuclear warheads, and the space-based missile defense system—dubbed the “Golden Dome” by former U.S. President Trump—all operate outside the old arms control framework. International Atomic Energy Agency Director General Rafael Grossi has warned that new technologies are creating regulatory gaps.

The narrow path leading to an unknown future.

The world has not entirely reverted to a state of zero-constraint jungle rules. Some risk management mechanisms established in the late Cold War period remain effective, such as the 1988 Ballistic Missile Launch Notification Agreement and the 1989 Strategic Exercises Notification Agreement. The agreement between the U.S. and Russia in Abu Dhabi to re-establish high-level military dialogue channels also represents a faint glimmer of hope on the front line. However, these measures appear fragile when compared to legally binding, verifiable limits on weapon quantities.

The road ahead is narrow and fraught with thorns. One path involves the U.S. and Russia reaching a provisional voluntary restraint agreement at the bilateral level to buy time for more complex multilateral negotiations. Another path is to initiate extremely challenging trilateral negotiations among the U.S., Russia, and China, but this would require Beijing to change its stance, which currently appears highly unlikely. The third, and most perilous, path is the absence of any new agreement, with all parties engaging in arms buildup based on worst-case assumptions, leading to a continuous deterioration of strategic stability and a sharp increase in the risk of miscalculation.

Deceased nuclear physicist Richard Garwin once warned that the sheer number of weapons itself could become the fuse for an explosion. In the absence of safety valves, a single miscalculation during a crisis could lead to global catastrophe. In this week of February 2026, the world bid farewell to an imperfect yet crucial era of nuclear restraint. What lies ahead is an uncharted territory that demands greater strategic wisdom, restraint, and diplomatic creativity—and time may not be on humanity’s side.