New START nears expiry as global nuclear arms control faces critical test

Editor's note: Li Pinbao is an associate research professor at the Institute of Public Policy, South China University of Technology. His research interests include Arctic science diplomacy, China-U.S. Arctic policy, and Arctic governance. The article reflects the author's opinions and not necessarily those of CGTN.

On February 5, 2026, the New Strategic Arms Reduction Treaty (New START) between the United States and Russia is set to expire, potentially ending the last remaining legally binding framework limiting the world's two largest nuclear arsenals. If no interim arrangement or successor is reached, the U.S. and Russian strategic forces would operate for the first time since the early 1970s without agreed constraints. The expiration comes amid ongoing conflict in Ukraine, strategic competition in the Arctic and renewed concerns over nuclear programs in the Middle East, and it would signal a significant retreat from nuclear restraint and predictability, with implications extending far beyond Washington and Moscow.

New START, signed in 2010 and extended in 2021 for five years, capped each side at 1,550 deployed strategic nuclear warheads, limited deployed intercontinental ballistic missiles, submarine-launched ballistic missiles and heavy bombers to 700, and restricted total deployed and non-deployed strategic launchers to 800. Beyond numerical limits, it established an extensive verification and transparency regime, including regular data exchanges, notifications, on-site inspections and a Bilateral Consultative Commission to address compliance issues. These measures reduced uncertainty, limited worst-case planning and provided insight into each side's nuclear posture. The treaty has been instrumental in reducing global nuclear stockpiles from roughly 70,000 warheads in the mid-1980s to around 12,000 today, demonstrating the value of sustained arms control in preventing unconstrained competition.

The treaty's effectiveness has eroded in recent years. Mutual inspections were paused during the COVID-19 pandemic, and in February 2023, Russia announced it was suspending participation, citing Western actions in Ukraine. While both sides have continued to signal adherence to core numerical limits, verification mechanisms and formal dialogue have largely collapsed. The Bulletin of the Atomic Scientists has highlighted rising nuclear risks, moving its Doomsday Clock in January 2026 to 85 seconds to midnight, the closest ever, citing intensifying nuclear competition, absent arms control dialogue and New START's impending expiration.

Policymakers now face a stark choice: whether to maintain some form of voluntary restraint or allow the last U.S.-Russia nuclear arms control pillar to disappear entirely. Russian President Vladimir Putin has proposed a one-year political extension of the treaty's core limits to buy time for negotiations, which U.S. President Donald Trump initially called "a good idea," though no formal agreement has been reached, raising the prospect of a gap period with no binding constraints. Negotiating a comprehensive successor treaty would be extremely difficult under current conditions, as it would require years of technical work on definitions, counting rules and verification mechanisms, as well as sustained diplomatic engagement and trust. Such conditions remain largely absent amid ongoing conflicts and deep mutual suspicion.

If New START expires without replacement, the immediate consequence would be the removal of caps on deployed strategic warheads and delivery systems. Both sides could respond by "uploading" additional warheads onto existing missiles, a technically feasible step that could be executed quickly. Daryl Kimball, executive director of the U.S.-based Arms Control Association, has warned that without a temporary agreement, the United States and Russia could expand deployed arsenals for the first time in more than 35 years. Such a move would increase costs, deepen mistrust, reduce transparency and elevate the risk of miscalculation during crises.

The treaty's verification and transparency measures have been critical to strategic stability, helping both sides understand each other's capabilities and intentions. Their disappearance would force military planners to rely on assumptions, raising the likelihood of worst-case planning and rapid escalation. More broadly, the collapse of New START would weaken the global nuclear governance system, undermining norms of restraint that have helped prevent catastrophe for decades. Its lapse just ahead of the 2026 Nuclear Non-Proliferation Treaty (NPT) Review Conference would send a troubling signal that nuclear powers are retreating from disarmament commitments, potentially exacerbating divisions between nuclear and non-nuclear states and complicating efforts to prevent proliferation.

In a world where major powers may abandon nuclear restraint, the pressures for proliferation could grow. Some non-nuclear states might seek stronger "nuclear umbrellas" from allies, while others could conclude that independent nuclear capabilities are necessary for survival. Recent developments, including Iranian Foreign Minister Ali Bagheri Kani's February 2, 2026, statement that Iran will not pursue nuclear weapons, may contribute to global stability and provide cautious reassurance.

China's position emphasizes strategic stability and responsible restraint. Beijing is not a party to New START and has consistently maintained a nuclear policy of no first use, keeping its arsenal at the minimum level required for national security. At the same time, China supports dialogue among nuclear-weapon states on risk reduction, transparency and confidence-building measures, calling for major powers to uphold their special responsibilities in preventing arms races and reducing nuclear risks. From this perspective, preserving some form of mutual restraint between the United States and Russia, whether through a temporary extension or a renewed political commitment, is not only in the interest of the two countries but also essential for global stability.

Even if New START expires, options remain to mitigate risk, much as they did during the brief four-month interval between START and New START. Voluntary restraint, sustained communication, crisis management mechanisms and multilateral engagement among the five recognized nuclear-weapon states could help prevent a complete breakdown of nuclear governance. Reaffirming that a nuclear war cannot be won and must never be fought, strengthening crisis hotlines and avoiding destabilizing deployments – including unconstrained missile defense initiatives such as the U.S. "Golden Dome" system and related space-based capabilities – would be essential to reducing global nuclear risks.

New START was never a perfect solution, but it has provided over a decade of predictability, limited nuclear expansion and a foundation of strategic stability amid increasing great-power rivalry. Its expiration will narrow the margin for error. Preserving even limited forms of restraint remains far preferable to entering an unconstrained nuclear future marked by heightened mistrust, accelerated modernization and growing proliferation pressures.