Efforts to control and reduce nuclear weapons did not fare well in 2023, and the near future offers little reason for optimism. Russia’s decision to ‘suspend’ the 2010 New Strategic Arms Reduction Treaty (New START), the absence of a US-Russian dialogue on nuclear arms control or risk reduction and China’s nuclear build-up are opening the path to a nuclear arms race.

Several steps to avoid that path are evident: fully implement New START, resume US-Russian discussions on a range of strategic stability issues and establish an ongoing dialogue with China on nuclear arms and related matters. Unfortunately, at present, it is difficult to see the major nuclear weapons states taking those steps.

A difficult year for arms control

The year 2023 did not treat arms control well. In February, Russia ‘suspended’ New START, the last active nuclear arms control agreement between the United States and Russia. Moscow said it would continue to observe the treaty’s numerical limits but would not implement the data exchanges, notifications and inspections key to treaty verification. Soon thereafter, Washington ceased implementing the verification provisions while also saying it would abide by the limits.

New START contains three numerical limits, which reduced US and Russian strategic forces to levels not seen since the 1960s. One limit constrains each side to no more than 800 launchers for intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs) plus nuclear-capable heavy bombers. A second limit constrains each to no more than 700 deployed ICBMs, SLBMs and heavy bombers (deployed ICBMs and SLBMs are missiles in launchers). National technical means of verification, such as spy satellites, should allow each side to monitor the other’s compliance with these two limits with high or fairly high confidence.

The third limit – arguably, the most important – constrains the number of strategic warheads on deployed ICBMs and SLBMs plus one warhead attributed for each deployed strategic bomber to no more than 1 550 for each side. Many deployed ICBMs and SLBMs on both sides carry fewer warheads than their capacity, and additional warheads in storage could be added to deployed missiles. Absent New START’s notifications and inspections, the sides will have reduced confidence that the other has not added warheads and remains within the 1 550 limit.

For years, China maintained 200-300 nuclear warheads, roughly comparable to Britain or France. That is changing.

New START went into limbo at a time when Washington and Moscow had no ongoing dialogue on nuclear arms control, strategic stability issues or risk reduction. In June, the United States tried to reopen discussions that it had, mistakenly, put on hold following Russia’s February 2022 assault on Ukraine. However, Russian officials, citing the deterioration of the broader bilateral relationship stemming primarily from the Russia-Ukraine war, declined to engage.

More bad news came in October. Russia revoked its ratification of the 1996 Comprehensive Nuclear Test Ban Treaty, citing the US failure to ratify. Since Russia, like the United States, remains a signatory, it has an obligation to take no actions that would defeat the purpose of the treaty. However, Moscow’s action made the international arms control regime a bit shakier.

Meanwhile, US concern grew about China. For years, China maintained 200-300 nuclear warheads, roughly comparable to Britain or France. That is changing. China has several hundred ICBM silos under construction, and the US Defense Department estimates that the country may have 1 000 nuclear warheads by 2030. Pentagon officials increasingly refer to China as a future nuclear peer competitor. This has led some to argue that the US military will need more strategic weapons than New START allows. In October, the Congressionally-mandated Strategic Posture Commission issued a report calling for increases in the planned numbers of US ballistic missile submarines, SLBMs, ICBMs and heavy bombers, among other things.

Possible arms control steps …

The international arms control regime is in trouble, and a three-way nuclear arms race appears to be a growing prospect. Reenergised arms control efforts could avert this and keep nuclear risk in check. Desirable steps include:

First, the United States and Russia should immediately resume full implementation of New START. That would allow both sides to have confidence that the other is observing all the treaty’s numerical limits (at least until February 2026, when the treaty will expire by its own terms) and provide a foundation on which to negotiate a successor agreement.

While these are obvious steps for averting the growing possibility of a nuclear arms race, it is difficult to see the three major players – Moscow, Beijing and Washington – taking them now.

Second, the United States and Russia should resume their dialogue on strategic stability issues. Among other things, that dialogue should address what arms control agreement might follow New START and whether it would cover strategic nuclear arms or, preferably, all US and Russian nuclear weapons. The dialogue should also address issues such as missile defence and long-range conventionally-armed strike systems.

Third, China should agree to a more formalised dialogue with the United States on its growing nuclear arsenal. For their part, US officials should be prepared to speak seriously to Chinese concerns about US missile defence and conventional strike systems.

Fourth, while Washington wants to engage China, Moscow wants to address British and French nuclear forces. The UN Security Council Permanent Five – Britain, China, France, Russia and the United States – have had a dialogue on nuclear weapons matters for well over a decade. It continues to meet, though its results are meagre. It could offer a venue for the Five to discuss multilateral steps. Numerical limits would be hard, given disparities in weapons numbers, so they could start with qualitative constraints. For example, they might consider agreeing that ground-launched intermediate-range missiles could carry only conventional warheads.

… and a grim reality

While these are obvious steps for averting the growing possibility of a nuclear arms race, it is difficult to see the three major players – Moscow, Beijing and Washington – taking them now. First, Vladimir Putin is not willing to ‘compartmentalise’ arms control, that is, to keep it going despite difficulties in the broader relationship. Russian officials have made it clear they will do nothing with the United States in the arms control or risk reduction area as long as Washington supports Ukraine in the Russia-Ukraine war. Putin seems to believe he can ‘punish’ the West for supporting Ukraine by weakening the international arms control regime.

Absent changes in the positions of the three, they are heading for a period of growing nuclear arsenals, growing expenditures and growing nuclear risk.

Second, although US and Chinese arms control officials met last November, Beijing appears reluctant to engage on a regular basis. China’s hesitancy to talk and its lack of transparency is leading Washington to make worse-case assumptions regarding the ultimate size of Chinese nuclear forces, assumptions that could shape decisions on the future US nuclear force posture.

Third, while Washington prefers to focus on limiting nuclear weapons, it would have to be ready to discuss, and perhaps even negotiate on, missile defence and long-range conventional strike systems, which seem to top the list of Russian and Chinese concerns.

Absent changes in the positions of the three, they are heading for a period of growing nuclear arsenals, growing expenditures and growing nuclear risk. Hopefully, sooner rather than later, they will recall the conclusion the United States and Soviet Union reached in the 1960s: at some point, adding more nuclear weapons while the other side does the same increases costs and risks but does not enhance security. That conclusion is precisely what led to the first strategic arms talks between Washington and Moscow in the first place.