New START Expires: What Happens Next?

A common-property resource is one from which all can benefit as long as all cooperate in its sensible management.   Sensible management means no seeking of unilateral advantage in ways that, if also pursued by others, could lead to the resource’s collapse.  The ocean, the atmosphere, and peaceful international relations are all global common-property resources in that sense. The collapse of any of them could end civilization as we know it, but the one that could destroy all that we value most suddenly is use of nuclear weapons in conflict, escalating into global nuclear war. .

In his famous 1968 essay, “The Tragedy of the Commons”, the biologist Garrett Hardin wrote that the protection of common-property resources depends on “mutual restraint, mutually agreed upon”. Clearly, an important bastion against the danger of nuclear war has been the mutual restraint embodied in international agreements on nuclear arms control and nonproliferation. Of the agreements restraining nuclear arms racing on the largest scale, the New START agreement between the United States and Russia is the most important surviving example. 

New START’s imminent expiration, which would quite likely be followed before long by the collapse of the Non-Proliferation Treaty of 1968, could well launch an era of unbridled, multipolar, nuclear-arms racing that ends in total disaster. Driving the world toward this outcome at the moment is that neither President Trump nor President Putin appears to recognize the surpassing importance of mutual restraint, mutually agreed upon (in the nuclear domain or any other, it seems).  The world can only hope they come to their senses and extend New START…as a start on the road to more sensible nuclear restraint everywhere.

As New START expires, for the first time in half a century, we will be living in a world with no agreed limits on the United States and Russia building up their nuclear forces. For decades, nuclear arms control has improved U.S., Russian, and global security and reduced the risk of nuclear war by reducing tensions, increasing predictability and transparency, and limiting nuclear forces of particular concern. The mere act of being able to discuss and reach agreements on limiting the most fearsome forces on each side tends to reduce perceptions that the other side is implacably bent on your destruction.

Achieving nuclear restraint in the future will be far more complex, in a more multi-polar nuclear world, with evolving technologies from precision conventional weapons to artificial intelligence complicating nuclear balances — but it remains possible, with the right mix of determination and creativity.  It’s better to explore the options for new accords before a buildup gets locked in. 

President Trump can take a major step for both American and global security by agreeing to President Putin’s offer, announcing a deal to keep both U.S. and Russian nuclear forces on a leash for now and launching talks with both Russia and China to explore whether the “better agreement” Trump envisions can really be reached.

The expiration of the New START treaty ushers in a world bereft of any formal, mutually agreed restraints on strategic nuclear arsenals of the two nuclear superpowers. While this is unlikely to result in an immediate spike in US and Russian stockpiles, it is a regrettable indication of just how moribund strategic arms control has become as a process of interaction between adversaries who nevertheless share a mutual interest in managing nuclear risks at a time when these risks are on the rise.

Among other things, the demise of arms control will put even greater pressure on the already stressed nonproliferation regime, within which the bulk of non-nuclear weapon states have been perennially dissatisfied with the progress of arms reductions to which the nuclear powers have committed.

The old global nuclear order is rapidly crumbling, but the new one is yet to emerge. Dangerous times.

The expiration of New START will free the U.S. to exceed the treaty limits of 1,550 deployed strategic nuclear warheads and 700 deployed launchers.  Advocates for expanding the U.S. strategic arsenal mainly cite the buildup of China's nuclear forces, which the Pentagon estimates currently at 600 "operational nuclear warheads" with 1,000 warheads expected by 2030. The Trump administration has several options in the near term to increase U.S. nuclear forces, including "uploading" additional warheads on existing land-based and sea-based missiles, reactivating additional launch tubes on the existing Ohio-class ballistic missile submarines, and designating additional long-range bombers for nuclear delivery. Russia has similar options to increase its deployed strategic forces beyond New START limits if the U.S. decides to pursue a buildup. How China would respond to a U.S. increase is unclear, especially because China refuses to divulge its current program of expansion. For both Moscow and Beijing, President Trump's plans to pursue a "Golden Dome" national missile defense system (no matter how impractical) are also likely to drive higher numbers, as well as additional development of "exotic" delivery systems designed to evade missile defense. 

Unfortunately, prospects are not good for additional arms control agreements to constrain nuclear expansion by the U.S., Russia and China.  While President Putin would likely agree to another bilateral U.S.-Russia treaty to replace New START - in order to limit the U.S. nuclear threat to Russia - President Trump has insisted that any new treaty include both Russia and China. China, however, rejects any treaty that would not give it nuclear equivalence with the U.S. and Russia, which the U.S. (and probably Russia) are not prepared to accept. So, for the time being, nuclear buildup seems like the most likely path.  

The pace and extent of this nuclear buildup - and its implications for strategic stability - remain to be determined.

Once New START is gone, both sides will soon feel pressures to increase the number of their warheads. Uncertainty will trouble both. Both have so-called national technical means—meaning assets to spy on each other—at their disposal to monitor the other. Still, both cannot be certain about the other’s intentions. Pressures will grow in their respective security establishments to break out of the previous New START restrictions, if only because ‘the other might do it as well.’ Russia could be the first to start racing, given that the process of uploading additional nuclear warheads is considered to be faster in Putin’s empire. But make no mistake: America will soon follow. The relative silence from Washington’s lawmakers on New START’s demise is the writing on the wall. Over several years, a consensus developed in the military-industrial complex of the capital: China is already racing with nuclear weapons. China and Russia are in cahoots. America is therewith facing a two-peer problem. America needs more nukes. This logic, which denounces diplomacy at the expense of unilateral militarism, will become the main driver behind the arms race of the 21^st century. It has all the ingredients of a successful bipartisan dogma: it’s powerful, simplistic, and wrong. The ones to suffer from this policy will be the American people. They will have to foot the massive bills that will come with arms racing. But the world is watching, too. Why should non-nuclear countries under the nonproliferation treaty continue to adhere to nuclear abstinence if the big three are never going to fulfil their disarmament promises? The new arms race could well end up razing the remains of the global nuclear order and opening the flood gates to unfettered proliferation. A brave new world. 

On February 6, 2026, New START will expire. The treaty has already been extended for the maximum of five years permitted by its Article 14. Unless U.S. President Trump and Russian President Putin strike a last-minute stopgap deal, this week closes an era of more than five decades of bilateral strategic nuclear arms control.

New START constrains the world’s two largest nuclear arsenals with warhead and delivery vehicle limits and intrusive verification. Those pillars have been under strain for years. On-site inspections were halted in March 2020 during the COVID-19 pandemic, and Russia suspended its participation in the accord in February 2023. But if the treaty formally ends without a bridge, near-term nuclear transparency hopes will fade. Incentives to expand arsenals and upload more warheads to missiles will rise.

The consequences will reverberate far beyond Washington and Moscow. U.S. allies may well be dragged into an arms race. Many non-nuclear-weapon states––particularly across the Global South––will also see this as a confirmation that the United States and Russia have abandoned their Article VI disarmament commitments in the Nuclear Non-Proliferation Treaty. The result will be to send a strong signal about the value of the bomb, just as dual-use civilian nuclear energy is poised for a global revival driven by climate goals and the AI data center boom.

But despair and resignation is not the right mindset for this moment. If Trump and Putin truly want a treaty, it could happen quickly. The deeper problem is the agenda. The United States has pushed to include China, cover novel systems, and restrict nonstrategic nuclear weapons. Beijing rejects trilateral talks because of arsenal asymmetries. Russia wants negotiations on the overall strategic balance, including missile defenses and long-range conventional strike capabilities. These starting positions are very far apart.

A future without strategic arms control is one with great existential risks to humanity from nuclear weapons. U.S. and Russian leaders would be wise to immediately issue a political commitment to remain under New START’s limits after the agreement’s expiration. Then, a verifiable successor should be negotiated for restored data exchanges, notifications, and on-site inspections.

With the expiration of New START, Russia regains formal freedom to expand its strategic nuclear forces beyond treaty limits. But Moscow’s likely response should not be understood as a rush toward numerical arms racing. Russian behavior will instead reflect a familiar pattern: preserve strategic deterrence at relatively stable levels while shifting competition into domains that are cheaper, less regulated, and more politically useful.

In the near term, Russia is likely to keep its deployed strategic forces close to former New START ceilings. Doing so serves several purposes. It sustains Moscow’s long-standing narrative that it is not seeking an arms race, avoids triggering immediate U.S. uploading or force expansion, and remains fiscally sensible under sanctions and wartime strain. Russian planners have long emphasized survivability over aggregate numbers, and New START’s ceilings were never viewed in Moscow as operationally constraining. Maintaining rough continuity in deployed strategic forces allows Russia to project restraint while preserving flexibility.

At the same time, Russia will almost certainly retain the option to upload additional warheads as a hedge rather than exercising it immediately. Systems such as the RS-24 Yars and the future Sarmat were designed with latent MIRV capacity, and Russian military-economic thinking prizes this kind of optionality. Uploading can be done selectively, incrementally, and reversibly, which makes it useful for signaling without provoking a dramatic response. The real constraints are not warhead availability but delivery-system bottlenecks, particularly reentry vehicles, guidance components, and production capacity. Those constraints favor gradual adjustment over visible breakout.

Meanwhile, Novel systems such as Avangard, Poseidon, and Burevestnik fit into this logic as asymmetric hedges rather than replacements for the triad. Their operational value is uneven and, in some cases, uncertain. But from Moscow’s perspective, they impose planning costs on the United States and provide insurance against future technological breakthroughs that could erode second-strike survivability. These systems also function as bargaining chips.

Diplomatically, Moscow is unlikely to pursue a New START–style successor focused on aggregate warhead limits. Instead, Russia will push for narrower arrangements aimed at constraining specific U.S. capabilities it views as destabilizing, including missile defense, long-range precision strike, and theater-range deployments in Europe. Any arms control proposal will be framed instrumentally, not as a normative commitment to restraint, but as a way to bind U.S. advantages while preserving Russian freedom of action elsewhere.

Finally, China will remain the silent driver of Russian hedging. Publicly, Moscow will continue to downplay Beijing’s role. Privately, China’s expanding arsenal reinforces Russia’s reluctance to accept any framework that locks it into parity with the United States while leaving China unconstrained.

The most likely outcome after New START is not a dramatic arms race but a steady pattern of selective adaptation. Russia will hedge, probe, and shift competition into less transparent domains, increasing ambiguity and complicating escalation control even in the absence of large numerical change.

If the expiration of New START heralds of new arms race, it won’t be with Russia. When historians explain why strategic arms reductions between the United States and Russia came to pass, they highlight the summits between Soviet General Secretary Mikhail Gorbachev and U.S. presidents Ronald Reagan and George H. W. Bush. Many credit the 1991 Strategic Arms Reduction Treaty (START I) to U.S.-Soviet détente, exemplified by Reagan’s remark during the 1988 Moscow Summit that when he had likened the Soviet Union to an “evil empire” five years earlier, “I was talking about another time, another era.” That arms control’s golden age coincided with the Cold War’s end was no accident; even so, the driving force behind vast reductions in nuclear arms between 1991 and 2011 was not diplomacy but rather geopolitics. As U.S. President George H. W. Bush’s national security adviser, Brent Scowcroft, observed in May 1991, weeks before the treaty’s finalization, “START is at best a modest contribution to security. The Soviet Union is no longer very important.”

The collapse of Soviet power, and the absence of a great-power replacement, marginalized nuclear deterrence in international affairs. The attention swung from arms control to nonproliferation, as nuclear weapons in new hands jeopardized America’s unmatched ability to project conventional power overseas. The demise of New START is, in similar fashion, less tied to deteriorating U.S.-Russian relations since Moscow’s seizure of Crimea in 2014 and invasion of Ukraine in 2022. The decline of arms control is instead bound up in the rise of a new great-power competitor—the People’s Republic of China and its expanding People’s Liberation Army Rocket Forces.

*The views expressed here are those of the author alone and do not necessarily represent the views, policies, or positions of the U.S. Department of Defense or its components, to include the Department of the Navy or the U.S. Naval War College.