Indian Council of World Affairs

Introduction 

On 5 February 2026, the New Strategic Arms Reduction Treaty (New START) between the United States and Russia is set to expire. Since its entry into force in 2011, New START has acted as the cornerstone of strategic nuclear restraint between the two largest nuclear-armed states in the world. Unlike earlier treaties such as the Strategic Arms Limitation Talks (SALT I & II), which focused only on numerical limits on missile launchers rather than reducing warheads or establishing detailed verification mechanisms, New START established a routine practice of verification, data exchange, and inspection that generated predictability and reduced misperception in the context of nuclear warheads owned by the two superpowers.^[i] Its expiry marks a moment of vulnerability for the global non-proliferation architecture, especially at a time when geopolitical competition is rising, trust between major powers is low, and nuclear arsenals are rapidly modernising. The critical question is whether the institutional infrastructure of restraint and transparency – upon which the non-proliferation regime depends – can survive this transition. 

What the New START Achieved

To understand the implications of the expiry of the New START Treaty, one must be aware of what it specifically provided. The New START, signed in 2010 and entered into force in February 2011, was a legally binding framework that imposed precise numerical limits, created institutionalised transparency, and embedded routine verification practices in the strategic nuclear relationship between the US and Russia.^[ii]

At the core of the treaty were quantitative ceilings on strategic nuclear forces. The treaty limited each party to a maximum of 1,550 deployed strategic nuclear warheads, a significant reduction from Cold War-era levels that exceeded 10,000 warheads per side. These warheads could be deployed only on a restricted number of delivery systems, such as intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers. These limits were designed not merely to reduce numbers but to shape force structures in ways that discouraged destabilising postures and excessive potential.^[iii] Crucially, New START introduced a simplified and transparent counting rule: each deployed heavy bomber counted as one warhead, regardless of the actual number of nuclear weapons it could carry. This rule reduced ambiguity and limited incentives to exploit technical loopholes, making compliance easier to verify and interpret.^[iv] By February 2018, both the United States and Russia had formally met these limits, a fact confirmed through treaty-mandated data exchanges.

The treaty’s other stabilising contribution was its verification and transparency regime. Under New START, the two countries were required to exchange comprehensive data on their strategic forces twice a year, including the exact number, type, and location of deployed warheads and delivery systems. In addition, the treaty mandated up to 18 on-site inspections per year for each party.^[v] These inspections were supplemented by a dense network of notifications, with more than 1,600 messages exchanged annually and covered events, such as the movement, conversion, or elimination of missiles and launchers.^[vi] Together, inspections and notifications provided each side with a near-real-time picture of the other’s strategic forces, dramatically reducing uncertainty. The significance of the treaty lies in how it reduced reliance on assumptions and intelligence estimates to knowledge that was based on a shared, verified dataset, backed by the right to physically inspect facilities. This routine interaction fostered a degree of predictability that endured even during periods of acute political tension, including after 2014, when relations between the United States and Russia deteriorated following the Ukraine crisis and Russia’s annexation of Crimea.^[vii]

Beyond its bilateral effects, New START also played an important normative role in the global nuclear order. By voluntarily accepting binding limits and intrusive verification, the two largest nuclear powers reinforced the principle that nuclear restraint is both possible and enforceable. 

Table 1: Trends in US and Russian Deployed Strategic Nuclear Warheads under New START (2011–2026)

Source: Arms Control Association 

Consequences and Effects of New START’s Expiry

In February 2023, Russia announced the suspension of its participation in the implementation of New START, marking a significant turning point in the treaty’s operational life. Although Moscow did not formally withdraw and stated that it would continue to observe the treaty’s numerical limits on deployed strategic nuclear warheads and delivery systems, it halted bilateral data exchanges and on-site inspections, effectively disabling the verification regime.^[viii] The United States subsequently suspended its own inspections, acknowledging that reciprocal implementation was no longer possible. This development is analytically significant because it underscores that New START’s stabilising value is derived less from its numerical ceilings than from the verification practices that made those ceilings credible.^[ix] With transparency mechanisms suspended, both sides have been compelled to rely more heavily on national technical means and intelligence assessments, increasing uncertainty and reinforcing worst-case planning. In this sense, the treaty was partially undermined well before its formal expiration, underscoring the ongoing erosion of arms control.

One of the most apparent consequences of New START’s expiry is likely to be a loss of structured transparency between the United States and Russia. Without an agreed framework for data exchange and inspection, both sides will rely more heavily on intelligence and remote monitoring, which are inherently imperfect and politically contested methods.^[x] In an environment of high geopolitical tensions, with both states contemplating larger stockpiles and faster modernisation, the lack of a verification framework would encourage worst-case planning and increase the risk of miscalculation.

A study by the Stockholm International Peace Research Institute notes that, often, the decision not to pursue a nuclear weapon is as much political and normative as it is technical. If the biggest nuclear powers appear unwilling to maintain limits, political arguments against proliferation become harder to sustain. The New START didn’t expire in isolation but against the backdrop of an increasingly multipolar nuclear landscape. China’s ongoing and rapid nuclear modernisation highlights that nuclear competition is no longer a bipolar contest between the United States and Russia.^[xi] China is expanding both the size and diversity of its nuclear forces, emphasising survivability and second-strike capabilities, a posture that differs significantly from the Cold War models of symmetry. For Beijing, joining a bilateral treaty modelled on New START would indicate a relative disadvantage, constraining a rapidly growing arsenal without addressing strategic asymmetries. For Washington and Moscow, conversely, ignoring Beijing’s trajectory raises strategic dilemmas about long-term stability and deterrence dynamics. This structural asymmetry complicates simplistic calls for a ‘renewed’ New START or for inclusion of all major nuclear powers in a single framework.^[xii] The pressing diplomatic question is therefore not whether China should be forced into a parity-based treaty but whether a new architecture of cooperation can accommodate asymmetric incentives while preserving crisis stability and transparency.

The SIPRI study also notes that the erosion of bilateral treaties has coincided with renewed emphasis on nuclear modernisation in multiple countries. It also highlights signs of a reversal of the long-term trend of nuclear reductions that marked the post-Cold War era. The loss of New START sends a message, especially to states that are technologically latent (capable of developing nuclear weapons but choosing not to do so), that restraint is negotiable.^[xiii] For countries in volatile regional security environments, the disappearance of disciplined restraint among major powers may create political space for arguments in favour of deterrent options. Proliferation decisions are not only technical calculations but also political ones, influenced by perceptions of international norms and expectations about the behaviour of great powers.^[xiv] When treaties disappear, norms become harder to anchor. The IAEA’s safeguards system remains important, but without visible examples of powerful states practising restraint, the leverage of multilateral instruments is diminished.

Conclusion

The expiration of New START is a watershed moment for the global nuclear order. Its immediate effect will be the removal of structured limits and verification routines between the United States and Russia. Beyond that, it carries practical consequences that risk weakening the moral authority of the non-proliferation regime at a time when the international system is already under pressure from geopolitical competition and asymmetric nuclear modernisation. The empirical risk is not mass proliferation in the immediate aftermath but a slow erosion of the practices and expectations that have constrained nuclear competition over the past three decades. The policy response must therefore be creative, adaptive, and resolutely grounded in an understanding that stability requires both transparency and political legitimacy.

Even as the treaty approaches its formal end, the absence of a legally binding treaty need not result in a complete breakdown of nuclear restraint. A more politically feasible pathway lies in continued information sharing among the United States, Russia, and China, aimed at reducing miscalculation rather than limiting arsenal development. Regular exchanges on nuclear stockpiles, force posture changes, and major modernisation activities could preserve a basic level of transparency without requiring new agreements that impose numerical ceilings. Such an approach reflects the structural differences between the contemporary nuclear landscape and the declining viability of formalised arms control. By prioritising risk reduction and crisis management– through advance notifications, selective data sharing supported by commercial remote sensing, and functional crisis-communication channels – nuclear diplomacy can reduce uncertainty and misperception, the key drivers of escalation risk. These efforts must be complemented by sustained support for the multilateral non-proliferation architecture, including a strengthened IAEA and continued political commitment to preserve global nuclear stability in a post-New START environment.

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*Tripti Neb, Research Intern, Indian Council of World Affairs, New Delhi
Disclaimer: Views expressed are personal. 

Endnotes 

^[i] US Department of State, "New START Treaty," Bureau of Arms Control, Deterrence, and Stability, https://www.state.gov/new-start-treaty.

^[ii] Nuclear Threat Initiative, "Treaty between the United States of America and the Russian Federation on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START),"https://www.nti.org/education-center/treaties-and-regimes/treaty-between-the-united-states-of-america-and-the-russian-federation-on-measures-for-the-further-reduction-and-limitation-of-strategic-offensive-arms/

^[iii] The Center for Arms Control and Non-Proliferation, "Understanding New START," fact sheet, https://armscontrolcenter.org/wp-content/uploads/2017/01/NewSTARTFactsheet.pdf.

^[iv] Arms Control Association, "New START at a Glance," fact sheet, last modified December 2024, https://www.armscontrol.org/factsheets/new-start-glance.

^[v] US Department of State, "New START Treaty," Bureau of Arms Control, Deterrence, and Stability, https://www.state.gov/new-start-treaty.

^[vi] Amy F. Woolf, The New START Treaty: Central Limits and Key Provisions, CRS Report No. R41219 (Washington, DC: Congressional Research Service) https://www.congress.gov/crs_external_products/R/PDF/R41219/R41219.61.pdf

^[vii] Robert Grenier, "Analysis: US-Russia Relations Drop to New Low," Al Jazeera, March 6, 2014, https://www.aljazeera.com/features/2014/3/6/analysis-us-russia-relations-drop-to-new-low

^[viii] Shannon Bugos, "Russia Suspends New START," Arms Control Today, March 2023, https://www.armscontrol.org/act/2023-03/news/russia-suspends-new-start.

^[ix]  Steven Pifer, Victor Mizin, and Patricia Jaworek, "The Uncertain Future of the New START Treaty," policy brief, Center for International Security and Cooperation, https://cisac.fsi.stanford.edu/publication/uncertain-future-new-start-treaty.

^[x] Amy Woolf, "Beyond New START: What Happens Next in Nuclear Arms Control?," Royal United Services Institute, https://www.rusi.org/explore-our-research/publications/commentary/beyond-new-start-what-happens-next-nuclear-arms-control

^[xi] Joseph Rodgers and Heather Williams, "Parading China’s Nuclear Arsenal Out of the Shadows," Center for Strategic and International Studies, https://www.csis.org/analysis/parading-chinas-nuclear-arsenal-out-shadows

^[xii] Mrityunjay Goswami, "Navigating the Nuclear Balance: The US—China's Evolving Strategic Posture," issue brief, The Indo-Pacific Studies Center, https://www.indo-pacificstudiescenter.org/briefs/us-china-nuclear-strategy-balance

^[xiii] Hans M. Kristensen and Matt Korda, "World Nuclear Forces," in SIPRI Yearbook 2025: Armaments, Disarmament and International Security (Stockholm: Stockholm International Peace Research Institute, 2025), 177–213, https://www.sipri.org/sites/default/files/SIPRIYB25c06%266A.pdf.

^[xiv] Mike Albertson, "Life After New START: Navigating a New Period of Nuclear Arms Control," Arms Control Today, https://www.armscontrol.org/act/2025-01/features/life-after-new-start-navigating-new-period-nuclear-arms-control.