New START Treaty Expires: Nuclear Arms Control Dilemmas and Global Risks in the Post-Treaty Era

On February 5, 2026, as the last legally binding nuclear arms control document—the New Strategic Arms Reduction Treaty—officially expired after the midnight bell tolled, the framework that had limited the number of nuclear weapons between Washington and Moscow for over half a century came to an end. This marked the first time since the signing of the Strategic Arms Limitation Treaty (SALT I) in 1972 that the United States and Russia faced each other's massive nuclear arsenals without any bilateral treaty constraints. United Nations Secretary-General António Guterres described this day as a moment of severe testing for international peace and security. In Abu Dhabi, UAE, although U.S. and Russian negotiators agreed to initiate new arms control talks as soon as possible, fundamental disagreements over the negotiation framework, along with the deadlock caused by the U.S. insistence on involving China in the talks—a move rejected by Beijing—heralded a dangerous and uncertain vacuum period for global strategic stability.

Technical Details and Immediate Consequences of Treaty Invalidation

The New Strategic Arms Reduction Treaty 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 the number of deployed intercontinental ballistic missiles, submarine-launched ballistic missiles, and heavy bombers as delivery vehicles at no more than 700. The treaty was originally set to expire in 2021 but was later extended by five years. In practice, the treaty's implementation mechanism had long been in name only. In 2020, due to the COVID-19 pandemic, on-site inspections stipulated by the treaty came to a halt. In February 2023, Russian President Vladimir Putin unilaterally suspended Russia's obligations under the treaty, citing the United States and NATO's public statements about defeating Russia, though at the time he still indicated that Russia would continue to adhere to the numerical limits. In September 2025, Putin proposed maintaining the treaty's core restrictions for another year to buy time for negotiating a new agreement, but this proposal received no response from the United States.

The immediate technical impact of the treaty's lapse is clear: there is no longer a legal cap on the number of nuclear weapons deployed by the United States and Russia. However, analysts point out that this does not mean the two countries will immediately embark on large-scale military expansion. Matt Korda, Deputy Director of the Nuclear Information Project at the Federation of American Scientists, analyzed that Russia is currently deeply mired in the conflict in Ukraine, and its nuclear industry modernization projects are not progressing smoothly, lacking the capacity to significantly accelerate the expansion of its nuclear arsenal in the short term. On the American side, its nuclear arsenal modernization plan has long been proceeding step by step, with the budget for nuclear modernization in fiscal year 2026 reaching as high as 87 billion dollars, including the development of the Columbia-class strategic nuclear submarines and B-21 stealth bombers. The lapse of the treaty primarily removes a psychological guardrail and a verifiable transparency mechanism. The U.S. Navy has already begun technical preparations to reactivate the launch tubes on Ohio-class strategic nuclear submarines that were previously prohibited by the treaty, which is seen as a clear signal.

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

The diplomatic game in the post-treaty era rapidly evolved into a complex tripartite interaction pattern, with each party's stance clearly defined.

The Trump administration in the United States viewed the expiration of the treaty as an opportunity to reshape the rules of the game. U.S. Secretary of State Marco Rubio made it clear the day after the treaty's expiration: arms control can no longer be just a bilateral issue between the United States and Russia. The core demand of the United States is that any new agreement must include China. At the United Nations Disarmament Conference held in Geneva, U.S. Deputy Secretary of State for Arms Control Thomas Dinanno accused China of having no restrictions, transparency, declarations, or controls over its entire nuclear arsenal. He also made a shocking allegation, claiming that the U.S. has intelligence indicating China conducted a secret nuclear explosion test on June 22, 2020, with a yield in the hundreds of tons, and attempted to conceal seismic monitoring signals through decoupling technology. The U.S. estimates that China's nuclear warhead count has increased from over 200 in 2020 to more than 600, and may exceed 1,000 by 2030. President Trump himself stated on social media that what is needed is a new, improved, and modernized treaty.

Russia's stance is more defensive and conditional. Kremlin spokesman Peskov stated that both Russia and the United States recognized the need to start negotiations as soon as possible during the talks in Abu Dhabi, but he denied reports of an informal six-month extension of the treaty, emphasizing that it is difficult to imagine any informal extension in this area. Russian Ambassador to the Geneva Conference on Disarmament, Gennady Gatilov, proposed a counter-condition: if the United States demands China's participation, then Russia also requires the U.S.'s NATO nuclear allies—the United Kingdom and France—to sit at the negotiating table as well. The Russian Foreign Ministry's statement reserves the right to escalate reciprocally, stating that it is prepared to take decisive military-technical measures in response to any new national security threats.

China firmly rejected the United States' attempts to draw it in. Ambassador Shen Jian, China's envoy for disarmament affairs, responded in Geneva that China's nuclear capabilities are far from reaching the levels of the U.S. and Russia, and therefore, it will not participate in nuclear disarmament negotiations at this stage. He accused the U.S. of hyping up the so-called "China nuclear threat" as a false narrative, aimed at shirking its own nuclear disarmament responsibilities and seeking excuses for nuclear hegemony. China expressed regret over the treaty's expiration and urged the U.S. to accept Russia's proposal and resume bilateral negotiations with Russia. Beijing's strategy is clear and consistent: it refuses any multilateral restriction framework until its nuclear arsenal reaches a scale comparable to that of the U.S. and Russia. Data from the Stockholm International Peace Research Institute supports China's claim: the U.S. and Russia together possess over 80% of the world's nuclear warheads, with each holding around 4,000, while China has only about 600, despite having the fastest expansion rate.

Regional chain reactions and nuclear proliferation risks.

The expiration of the New START Treaty has implications far beyond the trilateral relations among the United States, Russia, and China. It undermines the cornerstone of the global nuclear non-proliferation system gradually established since the end of the Cold War and may trigger a series of dangerous chain reactions.

First, the trust crisis among U.S. allies is intensifying. The Trump administration has repeatedly complained about NATO allies' insufficient defense spending, and its "America First" rhetoric has led allies dependent on the U.S. nuclear umbrella, such as Poland, Germany, and even Sweden, to openly discuss whether they need to develop independent nuclear deterrent capabilities. Former NATO Supreme Allied Commander Admiral James Stavridis once warned that once European countries begin to doubt the credibility of U.S. extended deterrence, the floodgates of nuclear proliferation could be opened.

Secondly, new weapon technologies are operating outside existing regulations. Russia's high-profile displays of the Poseidon nuclear-powered unmanned underwater vehicle and the Burevestnik nuclear-powered cruise missile, China's testing of a global-flight hypersonic weapon, and the United States' plans to build a "Golden Dome" space-based missile defense system—equipment referred to by The New York Times as science-fiction weapons—fall entirely outside the scope of traditional arms control treaties. Rafael Grossi, Director General of the International Atomic Energy Agency, has warned that these new technologies lack regulatory constraints, increasing the risk of miscalculation.

The deeper risk lies in the potential fundamental shift in the logic of global strategic stability. The Cold War-era theory of mutual assured destruction was built on a foundation of transparency and approximate parity in nuclear arsenals between the two sides. Today, with transparency fading, new types of weapons emerging, and the rise of third-party powers, decision-makers in various countries will have to plan their strategies based on worst-case assumptions. Experts from the Monterey Institute of International Studies point out that currently, as many as 40 countries globally possess the technical capability to develop nuclear weapons in the short term, with political will and international norms being the primary constraints. Once core norms are eroded, these thresholds could rapidly lower. In countries on the security frontlines, such as Japan and South Korea, domestic debates on nuclear armament are bound to intensify.

Into the Unknown: A Nuclear Age Without a Map

From a historical perspective, February 5, 2026 marks the end of an era. Since the United States and the Soviet Union initiated the Strategic Arms Limitation Talks in 1969, despite fluctuations in relations, maintaining strategic stability and avoiding nuclear war have always been the highest consensus between the two sides, leading to a series of treaties and confidence-building measures. Today, the foundation of this consensus is collapsing.

The road ahead is fraught with thorns. Negotiating a new multilateral nuclear arms control agreement will be far more complex than bilateral treaties. It requires balancing the diverse demands of the five legally recognized nuclear-weapon states (the U.S., Russia, China, the U.K., and France) as well as the de facto nuclear-armed states (India, Pakistan, Israel), while also covering new domains such as space, cyberspace, and hypersonic technology. Against the backdrop of intensifying strategic competition among major powers and unresolved conflicts in Ukraine and the Middle East, the political will to achieve such an agreement is virtually non-existent.

In the short term, the world may have to rely on some residual informal constraints, such as the 1988 Ballistic Missile Launch Notification Agreement and the 1989 Strategic Exercises Notification Agreement. However, as the late nuclear physicist Richard Garwin warned, the real danger lies in the sheer number of weapons themselves. When thousands of nuclear warheads are on high alert, coupled with poor communication channels and a lack of transparency mechanisms, a single miscalculation, a technical failure, or an accidental escalation of a conventional conflict could have catastrophic potential consequences.

The demise of the treaty is not with a bang, but a whimper. It takes away an imperfect yet crucial risk management framework, leaving behind an uncertain era where nations must rely on their own strength to navigate forward under the shadow of nuclear threat. The burden of global strategic stability has never weighed so heavily on such a fragile foundation.