5 February 2026
The expiration of the US–Russia New START nuclear arms control treaty without a replacement means that, for the first time in decades, there are no treaty-based limits on the world’s nuclear arsenals. While Russia has proposed a political commitment to the US to continue adhering to the treaty’s warhead and launcher limits, this offer should be viewed with suspicion.
The New START Treaty, which restricted the strategic nuclear arsenals of the United States and Russia, expired on 5 February 2026 without being replaced. In practice, the treaty had effectively been buried as early as 2023, when Russia violated it by announcing that it had “suspended” its participation, specifically with regard to the verification protocol involving on-site inspections and data notifications. Nevertheless, in September 2025, Russia proposed a political commitment to continue observing New START’s warhead and launcher limits for one year. However, the US has not indicated its readiness to accept the proposal. Under current conditions, maintaining New START’s central limits would have an adverse effect on NATO’s security, and European NATO members should hope that the US will instead seek to initiate a new round of arms control negotiations with Russia and China.
Arms control treaties, including those covering nuclear arms, are not ends in themselves but a means of increasing security. Bilateral treaties that constrain force structures, such as New START, are concluded between potential enemies who have assessed that accepting limitations on their own forces is worthwhile if, in exchange, they will be able to limit their adversary’s military power. As the benefits of such treaties are also affected by other political and material conditions, a treaty that once increased security does not automatically have the same effect at a later time. This is also the case with New START.
The rationale behind New START
When New START was first signed in 2010, Russia agreed to it because it did not restrict its non-strategic nuclear forces, or constrain its efforts to modernize its strategic nuclear forces. This was particularly relevant for the replacement of single-warhead Topol intercontinental ballistic missile (ICBM) systems with multiple-warhead Yars ICBMs, which allowed Russia to create an upload capacity for its ICBM systems that it had previously lacked. The United States, on the other hand, was only just beginning its modernization programme, and had few reasons to increase its strategic nuclear forces because it enjoyed overwhelming conventional superiority over Russia and could easily address Chinese and North Korean nuclear capabilities with its existing nuclear posture. As US targeting requirements were based on the Russian force structure, constraining that structure allowed the US to reduce its own forces accordingly.
This condition no longer applies because the targeting requirements of the US strategic nuclear forces are increasingly affected by China’s nuclear buildup, meaning that the US expects it must increase its deployed nuclear forces to be able to implement its nuclear strategy against both Russia and China. In 2021, it was already doubtful whether extending New START was in the US’s interest. However, there were sufficient reasons to do so at the time because China’s nuclear buildup was still in its early stages, and the treaty gave the US an opportunity to negotiate a replacement with verification mechanisms in place. Instead, Russia invaded Ukraine, violated the treaty, and no negotiations on a replacement took place.
China changes the equation
In 2026, the need for the US to strengthen its nuclear posture to deter both China and Russia is even more apparent. This is likely the reason why Russia has become interested in maintaining New START’s central limits, despite previously seeking to negotiate a new treaty that would also cover missile defences and strategic non-nuclear weapons. Not only can Russia expect the US to increase its nuclear forces in the near future, it also knows that the US considers it a secondary adversary compared to China. If the US were faced with the choice of whether to reserve warheads for Chinese or Russian targets, Russia could reasonably expect Chinese targets to be prioritized. Under these conditions, a US decision to continue adhering to New START’s central limits would have troubling implications for deterrence in Europe, even though the US does not need to maintain strict parity with both China and Russia.
As for Russia, New START does not cover its new strategic systems, such as Poseidon and Burevestnik, which means it could continue developing them without restrictions, as is already the case with non-strategic nuclear weapons. Moreover, as Russia’s current proposal does not include the restoration of the verification protocol, it would be very difficult for the US to assess whether Russia was complying with the agreement. This is a crucial deficiency, considering that Russia is notorious for being a serial violator of arms control pacts and pledges. In the nuclear realm, the list includes at least Russia’s Presidential Nuclear Initiative to reduce non-strategic nuclear forces, the INF Treaty banning ground-launched intermediate-range missiles, and New START itself. Even if Russia agreed to restore the verification protocol, verification alone would not alleviate US targeting requirements and would still leave Russia in an advantageous position.
The European NATO members should therefore be relieved that there are no indications that the US intends to accept Russia’s proposal to continue observing the treaty’s quantitative limits. Nuclear arms control should, of course, be pursued if there is a reasonable chance of concluding an appropriate treaty for the contemporary security environment. Such a treaty would preferably include the US, Russia and China, and would cover all types of nuclear weapons. New START, for its part, was designed for the post-Cold War world of two large nuclear powers, but in the era of nuclear multipolarity and China’s emergence as the US’s main adversary, it has simply become outdated.
Photo: Jewel Samad / AFP / Lehtikuva
