Dr. Bahar Akın*

The End of a Treaty, the Erosion of a Regime

The expiration of the New START Treaty on February 5, 2026, marks more than the end of the last legally binding nuclear arms control agreement between the United States and Russia. It signals a deeper and more consequential shift: the gradual disintegration of the international framework that has sought, for decades, to limit nuclear weapons through shared rules, predictability, and restraint.

This transformation became immediately visible one day later at the Conference on Disarmament in Geneva. Statements delivered by representatives of the United States, Russia, and China revealed not only diverging strategic priorities, but also the erosion of a shared conceptual language that once made nuclear arms control possible.

What New START Provided and What Has Been Lost

Signed in 2010, the New START Treaty imposed numerical limits on deployed strategic nuclear warheads and their delivery systems while establishing verification, data exchange, and inspection mechanisms. Its value, however, extended far beyond numbers.

New START created a framework of predictability. By offering transparency into capabilities and force structures, it reduced the risk of miscalculation, escalation, and worst-case assumptions during periods of crisis. With its expiration, this stabilizing foundation has disappeared, leaving behind uncertainty rather than mutual reassurance.

The United States: Arms Control Must Not Constrain Deterrence

Speaking in Geneva, U.S. Under Secretary of State for Arms Control and International Security Thomas DiNanno framed New START as a product of a bygone strategic environment. According to Washington, a bilateral treaty designed in 2010 no longer reflects the realities of 2026.

The U.S. argument rests on three pillars. First, China’s rapid and opaque nuclear expansion. Second, Russia’s large stockpile of non-strategic nuclear weapons and the development of novel systems outside New START’s scope. Third, the growing nuclear capabilities of North Korea. In this context, Washington views bilateral arms control as insufficient and, increasingly, as a one-sided constraint.

DiNanno’s remarks reflect a broader shift in U.S. thinking. Arms control is no longer treated as a normative objective in itself, but as a conditional instrument that must not undermine deterrence. References to nuclear modernization, expanded force options, and even renewed testing underscore this transformation. Stability, in this view, is achieved through flexibility and strength rather than legally binding limits.

Russia: Stability Cannot Exist Without Balance

The  Permanent Representative of the Russian Federation to the United Nations Office and Other International Organizations in Geneva Ambassador Gennady Gatilov response directly challenged the U.S. framing. Moscow emphasized that despite its flaws, New START played a critical role in restraining strategic competition and maintaining predictability. Its termination, Russian officials argued, removes the last remaining legal barrier to an unconstrained nuclear arms race.

From Russia’s perspective, strategic stability cannot be reduced offensive weapons alone. The expansion of U.S. missile defense systems and NATO’s role in the Ukraine conflict are portrayed as destabilizing factors that undermined the treaty’s foundations. Consequently, Russia presents its development of new nuclear systems not as aggressive choices but as compensatory measures designed to restore balance.

Moscow also highlighted its 2025 proposal for voluntary post-New START restraints, which received no positive response from Washington. This episode illustrates the depth of the trust deficit and reinforces the perception that arms control has become subordinate to broader geopolitical confrontation.

China: Responsibility Lies With the Largest Arsenals

China’s intervention in Geneva introduced a different dimension to the debate. China’s ambassador on disarmament, Shen Jian reaffirmed its commitment to a no-first-use policy and to maintaining nuclear forces at the minimum level required for national security. At the same time, it rejected U.S. accusations of a “China nuclear threat” as misleading and politically motivated.

China argued that the primary responsibility for nuclear disarmament rests with states possessing the largest arsenals, the United States and Russia must take the lead in reducing their stockpiles before expecting broader multilateral engagement. China also criticized U.S. missile defense programs, extended deterrence arrangements, and nuclear cooperation initiatives as sources of global instability.

Yet China’s refusal to participate in multilateral disarmament negotiations exposes a fundamental contradiction. While expressing concern over the erosion of the arms control regime, Beijing remains reluctant to assume the responsibilities of a co-architect of a new framework.

The Core Problem: A Shared Vocabulary Has Disappeared

Taken together, the positions articulated in Geneva point to a deeper structural problem. The challenge facing nuclear arms control today is not merely the absence of a new treaty, but the collapse of a common language.

For the United States, strategic stability increasingly means the freedom to adapt deterrence to emerging threats. For Russia, it is inseparable from limitations on missile defense and the preservation of military balance. For China, stability is linked to maintaining the status quo while avoiding formal constraints. When identical terms carry fundamentally different meanings, arms control ceases to function as a regime.

Conclusion: A New Nuclear Era, a More Fragile Order

The post–New START world is not defined by the absence of a single agreement, but by the unraveling of the shared understanding that once sustained nuclear restraint. As treaties give way to unilateral flexibility and strategic ambiguity, the risks of miscalculation and escalation grow.

Geneva offered a glimpse into this emerging reality. The world is entering a new nuclear era, one marked not by disarmament, but by contested norms and fragmented responsibility.. In the absence of a shared language of restraint, nuclear weapons are no longer managed risks but expanding political tools  and past experience shows that such tools rarely remain under control for long.

*Bahar Akın is a researcher specializing in international security, nuclear non-proliferation, and international regimes. She received her PhD in Nuclear Disarmament and Non-Proliferation from the University of Vienna. Her research focuses on multilateral institutions, sanctions mechanisms, and strategic developments in the Middle East.