The run-up to and first eight months of Russia's 2022 full-scale invasion of Ukraine were characterised by near-constant nuclear sabre-rattling from Moscow. Though attempts at nuclear-armed coercion go back to the earliest days of the atomic age,¹  President Vladimir Putin's gambit ignited in the West possibly the most serious public concern about general nuclear conflict since the end of the Cold War. As these tensions have now somewhat eased²,  it may be time to ask: what will the lasting effects of Russian threats prove to be on the global nuclear order? What new risks do we face and how can states act to address them?

The most intense period of Russian escalatory rhetoric lasted approximately nine months, beginning about a month before the invasion and stepping up significantly once fighting had begun. Emanating both from Russian officials and from state-run media, the threat-making was closely tied to a broader Kremlin narrative; one which characterises the war not as an act of unprovoked, expansionist aggression on the part of Russia, but as a "proxy war" the US and NATO are waging against Russia.³

In keeping with this theme, the Kremlin's threat-making initially focused on NATO countries, promising nuclear attack if they directly intervened or increased their aid to Ukraine past varying limits. From September 2022, Russia shifted to making more direct threats of nuclear use inside Ukrainian borders in response to actions the Kremlin claimed Ukraine was planning (i.e., use of chemical weapons or a dirty bomb, attacks on nuclear power plants, etc.) or in the event of a Ukrainian breakthrough.^{4 5}   

Finally, in late October 2022, after more than a month of especially high tensions, Putin appeared to back down. The President denied Russia had ever been considering use of nuclear weapons and the Kremlin's rhetoric on the subject has been more muted since.⁶  Assessing the success of Putin's attempted nuclear coercion is difficult because so much depends on what the Russian president hoped to achieve. That can only be known by Kremlin insiders and may not have been clearly defined.

The threats directed at Kyiv are easiest to assess.  If the aim was to convince Ukraine to accept some kind of settlement or simply limit its battlefield ambitions, Moscow's attempt failed. The Kyiv government continues to be vocal in its desire to see the country returned to its 1991 borders,⁸  and despite setbacks, continues to plan with a view to eventual achievement of that goal.⁹  Moscow's pledge to use unlimited force to defend its annexed Ukrainian territory failed to deter Kyiv at all.

It remains unclear precisely what Russia hoped to achieve by accusing Ukraine of planning to use a dirty bomb or mount some other chemical/radiological attack. Some analysts theorize it was meant as justification for a potential escalation in the war, possibly including nuclear use.¹⁰  If this was the intent, it was also a failure. Putin felt the need to explicitly take the nuclear option off the table just a few weeks later, likely due to pressure from friendly countries, especially China.^{11 12}   Russia has not meaningfully escalated the war with Ukraine, despite the obvious motivation to do so as it suffers mounting losses without any real progress towards its war goals.¹³

Russian threats towards NATO have produced more complex results. Many have simply been unnecessary. NATO has refrained from becoming directly militarily involved in the conflict or imposing a no-fly zone over Ukraine, but there is no indication any such actions were ever being considered.

What Western countries have been doing is providing critical political, material and intelligence support for the Ukrainian war effort. This aid is the target of Russia's coercive diplomacy, but precisely how much Putin and his advisers hoped to achieve by the use of nuclear threats is unclear. At times they have demanded a total end to NATO support, and at others they have cautioned against increases in or new kinds of support, setting a variety of supposed red lines.^{14 15} 

Despite this, the quantity and sophistication of NATO's support has increased significantly since February 2022, doing so precisely during the period when Russia was issuing its most stringent threats.¹⁶  Stated Russian red lines have been crossed, provoking no meaningful response.¹⁷  On the other hand, NATO has exhibited caution in the face of the Kremlin's bellicosity and would have been able to ramp-up aid more quickly and act more freely absent fears of escalation.¹⁸  Measures such as the shipment of tanks and fighter jets to Ukraine were delayed somewhat for exactly this reason.

Russia's sabre-rattling has kept Ukraine's allies on edge and shaped their behaviour in a manner that benefited Russia, but to a limited extent. Moscow managed to, at best, buy itself time. It is difficult to say for sure, but it seems highly likely that Putin had loftier goals in mind which were not fulfilled.

A holistic assessment of the fallout from Russian brinksmanship must consider more than merely the extent to which Moscow's strategy succeeded. Explicit nuclear threats are an enormous step for a leader to take, and such an emphatic and sustained campaign of attempted coercion will have reverberations for years to come.

Arms Control & Strategic Stability

The most obvious consequence thusfar is the near-total collapse of the arms control regime between the US and Russia, who between them possess about 90% of the world's nuclear weapons.¹⁹  This unravelling began earlier; President Donald Trump withdrew the US from the Intermediate Nuclear Forces (INF) treaty in 2018, and the process can even be traced as far back as the Bush administration's abrogation of the Anti-Ballistic Missile treaty.²⁰  Russia's invasion was arguably the final nail in the coffin, in particular with the country's February 2023 suspension of New START – the last of the US-Russian arms control treaties. This was not explicitly linked to Russia's nuclear threat-making but is enmeshed in the Kremlin strategy to make Ukraine the central issue in all its dealings with the West and is another example of the Russian nuclear arsenal as a diplomatic weapon. Furthermore, if Russia strives to sow uncertainty and leave open the possibility of nuclear use, blocking US inspectors' access to its nuclear bases clearly serves that goal.

While Moscow has said it will continue to comply with the limits on deployed warheads set out in NEW Start, and US intelligence seems to corroborate this,²¹  the suspension has significant practical and symbolic effects. Symbolically, the treaty is not only the last remaining plank of the strategic arms limitation regime between the two countries, but it is also the largest and most important, setting limits on the total sizes and structures of the two strategic arsenals.²²  Its suspension signals a dire future for arms control more generally. It seems highly unlikely now that a return to the INF treaty can be negotiated, let alone an extension of New START beyond its expiration in February 2026.

In practical terms, the end of mutual inspections and deployment data sharing between the nuclear superpowers will significantly degrade trust and overall strategic stability between them.²³  The risk of miscalculation or misinterpretation of signals or accidental conflict in a crisis is heightened when each side has less certainty.   

The Nuclear Taboo

Russia's campaign of threats has a complex, bi-directional relationship with the "Nuclear Taboo" – the strong international norm against the use of nuclear weapons.²⁴  In one sense, Putin's failure to achieve his probable aims and his eventual climbdown can be seen as a consequence of and victory for the taboo, and one which is likely to reinforce it. Putin backed down after the Chinese government issued an unusually strong statement condemning the notion of using nuclear weapons in the war in Ukraine.²⁵  As ever, the exact reasons behind and influences on Russian decision-making are difficult to determine from the outside. But given Russia's increasing dependence on China for diplomatic and economic support,²⁶  and  the short time between the Chinese government breaking its silence and Moscow's climbdown, it seems highly likely that China's intervention was a key factor.^{27 28}   In private, this is an explanation supported by Chinese officials.²⁹  Also important were condemnations from India³⁰ and a majority of the G20 nations.³¹ This is an example of the taboo working; Putin was swayed primarily not by threats of forceful retaliation, but by an incentive not to harm Russia's standing among countries which he desires friendly relations. The longer the taboo continues to hold, especially after instances in which it clearly acted as a restraint, the more embedded it becomes as a norm governing international states' actions.³²

On the other hand, while Moscow was forced to climb down from its threats, it suffered no serious adverse consequences. The West did not punish Russia in any substantive way, likely because it was already using all the available political and economic tools in response to the war writ large. China, India, and various other nations with close or fair ties to Russia did issue warnings, but there is no indication of lasting damage to these relationships. India's cancellation of its annual summit with Russia was the most serious reaction, but Indian officials explicitly said the countries' bilateral relationship remained strong, nonetheless.³³

Thus, though the gambit failed to produce any significant results, its costs were comparatively low for Moscow. Insofar as it sowed some uncertainty in the West for a time and slowed the ramp-up of aid to Ukraine, it is possible to interpret it as having been worth attempting. When other leaders of nuclear-armed states consider whether to attempt such coercive diplomacy, they may recall this lack of negative consequences and conclude that campaigns of nuclear threats are worth attempting; that Putin's problem was merely a failure to establish sufficient credibility, perhaps because he did not actually move or stand up any nuclear forces. In this way, though the taboo against nuclear use held fast and may have been strengthened, the norm against nuclear threat-making appears to have been weakened. That latter norm does clearly exist, since Russia was convinced to stop by a broad coalition of states, but the fact remains that it was flagrantly violated for almost a year with no repercussions to the violator.

This strengthening and weakening of two different levels of norms governing nuclear weapons in international relations mirrors the Stability-Instability Paradox, a phenomenon in which nuclear weapons may encourage low-level conflict as states believe their adversaries will act to prevent dangerous escalation.³⁴ Nuclear first use has been rendered less likely, but nuclear sabre-rattling has been encouraged.

There is little doubt that February 24, 2022, marked a turning point in post-Cold War geopolitics. Things will never go back to the way they were before the Russian invasion of Ukraine, and the nuclear realm is no exception. Though Moscow's attempt at nuclear blackmail was largely unsuccessful, its legacy is a global landscape with heightened strategic uncertainty and less clear norms governing nuclear weapons. The Bulletin of the Atomic Scientists' decision in January 2024 to keep its "Doomsday Clock" at 90 seconds to midnight, where it was moved at the beginning of 2023, is reflective of the risks posed by this new state of affairs.³⁵

On the other hand, it is significant that China and other Russian-aligned states intervened diplomatically at the moment of greatest tension. Beijing recognised that it would be worse off in a world with more nuclear brinkmanship, and this overrode its evident desire to see the West kept off-balance and distracted by Russia. A range of states who otherwise struggle to see eye-to-eye on almost any issue were able to act in concert, not because other disagreements or rivalries ceased to exist, or as part of negotiated cooperation; but out of clear, shared interest. Careful leadership from the right states could leverage this unlikely coalition to address rising nuclear risks.³⁶  Whether by rebuilding the global arms control regime on a multilateral basis or reinforcing behavioural norms restraining nuclear blackmail through joint statements or other declaratory measures, there is a rare window of opportunity to make the world safer

Jack Kennedy is a Master in International Affairs student at Johns Hopkins University SAIS Europe, originally from Dublin, Ireland. He obtained his Bachelor in Computer and Electronic Engineering from Trinity College Dublin. There he served as Editor-in-Chief of Trinity News, Ireland's oldest student newspaper, before going on to work in journalism professionally. His research primarily concerns nuclear weapons, strategic stability, and arms control.