By Camilla Braito and Patrick Haasler - Russia Desk

Introducing the New START     

During the Cold War, nuclear arms control stood as one of the key pillars of international stability and as a guarantor of predictability in states’ behaviour. Today, that foundation is faltering. The idea of quantitatively or qualitatively reducing nuclear arsenals clashes with a growing global call to rearm, both in the nuclear field and beyond. Nowhere is this tension more visible than in the uncertain future of the New Strategic Arms Reduction Treaty (New START).

Signed by the United States and the Russian Federation in 2010 and entered into force on February 5, 2011, the New START replaced the 1991 START I, renewing both parties’ commitment to verifiably reduce their strategic nuclear arsenals. The Treaty sets three main limits. First, it caps the number of nuclear warheads deployed on intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers equipped for nuclear armaments. Second, it restricts the number of deployed delivery systems, including ICBMs, SLBMs, and nuclear-capable bombers. Third, it limits the total number of deployed and non-deployed launchers and bombers. Within these constraints, each side retains the freedom to structure and modernise its strategic forces at its discretion. A central feature of the New START is its monitoring and verification regime. This relies on the use of National Technical Means (NTM), a shared database updated twice a year with data on the numbers, types, and locations of Treaty-limited systems, as well as two types of on-site inspections to confirm accuracy and proper implementation. This arrangement, however, has already been on life support since 2020, when the COVID-19 pandemic interrupted on-site inspections and the two signatories never agreed on their resumption. In February 2023, the situation aggravated when Russia further suspended its participation in the Treaty, citing Washington’s hostile policy and support for Ukraine, just weeks after renewed compliance disputes.

Originally, the New START was set to last ten years, until 2021, with the option of a single five-year extension to 2026. Beyond that, no further renewals were envisioned. Within this framework, Moscow’s September 22, 2025, proposal to Washington to voluntarily continue adhering to the Treaty’s limits for one additional year after its expiration has particular significance. After warning in July that allowing the New START to lapse would be highly undesirable, on October 5, Donald Trump responded positively to the Russian proposal, although without making any formal commitment. A few days later, Vladimir Putin confirmed ongoing contacts with the U.S. through diplomatic channels, suggesting that four months should be sufficient to decide on an extension. However, he added that if the U.S. did not consider the continued adherence worthwhile, it would not be critical for Russia, whose nuclear deterrent capabilities continue to advance, most notably with the Poseidon system, a development that poses a game-changing challenge to traditional deterrence.

The delicate balance of incentives and apprehensions surrounding the Treaty’s future sets the stage for exploring the motivation behind Russia’s proposal for an extension. 

Russia’s offer in context: strategic motives and technological leverage

Strategic deterrence between Russia and the U.S. has become increasingly tense following the erosion of Cold War–era nuclear arms control. Following the dissolution of the INF Treaty in 2019, both countries reintroduced intermediate-range systems to Europe, reigniting mutual suspicion. The U.S. development and potential deployment of Tomahawk and Typhon missile systems in Europe - and possibly in Ukraine - has revived Russia's long-standing fears of a preemptive "decapitation strike" that could target its leadership with little warning. Moscow interprets the short flight times and high precision of these American weapons as a direct threat to its command structures, reminiscent of Soviet-era concerns during the 1980s Euromissile crisis. Washington argues that these deployments are defensive and necessary to counter Russian violations and capabilities, such as the SSC-8 missile and hypersonic systems. Nevertheless, Russia’s leadership views the situation as growing encirclement and has warned of retaliatory measures if U.S. systems move closer to its borders. This dynamic has reintroduced instability into the European theatre, with both sides signalling and counter-signalling under the shadow of mutual deterrence. Thus, the renewed presence of American long-range missiles in Europe symbolises a broader breakdown in trust and the return of Cold War–style anxieties about nuclear first strikes.

Against this tense backdrop, Russia’s revised nuclear doctrine, announced in December 2024, broadened the conditions under which nuclear weapons could be employed, including in response to an attack by a non-nuclear state supported by a nuclear power. This is consistent with Moscow’s fear of a potential U.S. transfer to Ukraine of Tomahawk missiles that can be nuclear-armed and for that are considered a direct and destabilising threat, reinforcing concerns about strategic vulnerability and justifying the lowering of its nuclear threshold. The "dirty bomb" alluded to by Kremlin spokesman Dmitry Peskov, which, in the event of an attack on the Russian Federation, would render it impossible to differentiate between conventional and nuclear armaments, is regarded by Russia's preeminent security elites as a grave threat to Russian sovereignty. This threat is met with a range of proactive, preemptive (non-nuclear), and reactive (tactical nuclear) countermeasures.

Assuming that Russia is solely interested in a deal with the U.S. because of the perceived threat posed by the Tomahawks would once again oversimplify the issue. The following brief outline of the latest technical and military developments will substantiate the assumption that Russia is attempting to force the Americans to the negotiating table from a position of strength. Russia has recently increased its pace of development and production of the intermediate-range missile Oreshnik, with a reported first combat use in November 2024 in the Ukrainian Oblast Dnipropetrovsk, and mass production declared in mid-2025. The system is characterised as mobile, solid-fuel, capable of speeds beyond Mach 10, equipped with multiple independently targetable re-entry vehicles (MIRVs), and capable of carrying submunitions. Due to its range (potentially up to 3,000–5,500 km) and hypersonic speed, the Oreshnik missile challenges existing missile defence systems and revives the risk posed by ground-launched intermediate-range ballistic missiles (IRBMs) since the collapse of the INF Treaty. Meanwhile, Russia claims that the nuclear-powered cruise missile Burevestnik (9M730) has successfully undergone very long endurance tests (14,000 km over 15 hours) and is approaching deployment. Its lower-altitude flight profile and seemingly unlimited range are designed to evade missile defence systems, representing a significant shift in the design of strategic weapons. Even though substantial technical uncertainty remains, particularly regarding the nuclear reactor propulsion unit, post-flight guidance, and operational safety, it can be expected that the missile will undergo further technical improvement and is therefore seen by many experts as a potential game-changer that could put the United States under immense pressure. 

Another strand of novel Russian strategic capability is represented by the Poseidon unmanned underwater vehicle (nuclear-powered torpedo), which is designed to travel long distances underwater, carry a high-yield thermonuclear charge, and threaten coastal infrastructure and naval bases. Due to the extensive nature of U.S. coastal and marine infrastructure, some analysts describe Poseidon as a "strategy-changer" in the maritime nuclear domain. These systems are important because they have the potential to degrade existing U.S./NATO missile defence and deterrence architectures, and they signal Russian strategic resolve. By introducing weapons that evade or challenge existing defence layers, Russia aims to tip the scales of nuclear and conventional deterrence in its favour and signal a determined position of strength on a tactical and strategic level. The U.S., so far, is lacking equivalent public breakthroughs. Russia's recent tests of the Burevestnik nuclear-powered cruise missile and Poseidon underwater drone are portrayed as revolutionary, providing unlimited range and the ability to loiter indefinitely, thus ensuring strategic parity for the entire 21st century. These systems are said to blur traditional missile categories, making them nearly impossible to verify or limit under existing arms control frameworks. Overall, the absence of reciprocal control mechanisms and growing distrust could fuel an uncontrolled arms race and heighten global nuclear danger.

All these things considered, it can be argued that Russia is leveraging technological innovation not merely as a means of deterrence but as a political instrument to restore strategic balance and compel renewed engagement from Washington. The shift from perceived vulnerability to technological assertiveness forms the backdrop for Russia’s new weapons programs and its current approach to arms control negotiations.

What comes next for the New START?     

Three possible scenarios on the New START could unfold after February 5, 2026. In the first, Moscow confirms the proposed commitment, and Washington agrees to reciprocate, allowing both parties to continue voluntarily observing the Treaty’s quantitative limits for one more year, notwithstanding other major divergences, mainly on the war in Ukraine. In the second, the Treaty expires without any time-bound effort to uphold its provisions, and in the absence of a successor arms control arrangement, the two largest nuclear arsenals may go unconstrained for the first time in more than three decades. In the third scenario, negotiations begin on a new agreement addressing strategic nuclear arsenals, either bilaterally or with China involved, at least in the early stages. Indeed, China’s growing capabilities provide strategic cover for Russia and reduce the leverage of traditional U.S.–Russia arms control, highlighting the need for a multilateral framework. This final scenario could develop independently or alongside one of the previous two, provided there is sufficient political will to initiate sustained talks. As both parties remain preoccupied with other urgent matters, it is unlikely that such an initiative will advance on its own; rather, it would likely progress in parallel with either an extension or the definitive termination of the existing Treaty. 

This range of possible outcomes sheds light on how the trajectory of the New START reflects the state of U.S.–Russia relations, the impasse in Ukraine, and the broader decline in genuine commitment to non-proliferation goals.

Conclusion                      

As things stand, the New START remains the only existing nuclear arms control treaty between the United States and Russia. When it expires in 2026, there will be no formal, legally binding limits on strategic nuclear arsenals for the first time in decades. Since a further formal renewal is not permitted under its current terms, serious concerns about the future of global arms control and strategic stability arise. 

Russia seeks to extend or replace the New START from a perceived position of strength, leveraging its recent breakthroughs in novel strategic weapons to force the United States back to the negotiating table, preferably on Moscow’s terms. These systems are designed to bypass or overwhelm U.S. missile defences, restore strategic parity after the INF Treaty’s collapse, and counter perceived encirclement by NATO, particularly the potential deployment of nuclear-capable Tomahawk missiles in Europe or Ukraine. By showcasing technically advanced, hard-to-intercept delivery vehicles and broadening its nuclear doctrine, Moscow aims to deter further Western escalation while signalling that any future arms-control agreement must account for these game-changing capabilities and address Russia’s core security concerns.

More than ever, the not-so-distant prospect of the New START reaching the end of its validity highlights the enduring importance of nuclear arms control for global security. Arms control embodies a paradoxical form of partnership, one in which rivals cooperate to co-manage deterrence and reduce the risks inherent in their competition. In essence, such agreements serve to uphold strategic stability, preserve crisis stability, and prevent the escalation of arms races, reminding us that even limited and imperfect cooperation is preferable to the absence of any attempt at regulation and that the willingness of states to negotiate in bona fide is a precondition for arms control efforts to work out. 

It remains incumbent on the American and Russian leadership to balance technological advancement with diplomatic engagement, seeking paths to stabilise deterrence beyond mere temporary extensions. The coming months are crucial for shaping the future of nuclear arms control and reducing strategic risks in an increasingly complex geopolitical environment.