The invasion of Ukraine in February 2022 and subsequent nuclear threats have sparked a wave of militarization in Europe, pushing Finland and Sweden to seek NATO membership. The perception of unpredictable and revanchist Russia has led the alliance to boost its deterrence capabilities, focusing mainly on conventional forces. Poland is among the countries that have expressed interest in hosting nuclear weapons from the United States, specifically entering NATO’s ‘nuclear sharing’ arrangements. This includes Belgium, Germany, Italy, the Netherlands, and Türkiye, which host US non-strategic B-61 nuclear bombs and operate dual-capable aircraft (DCA) capable of carrying them.
Poland’s interest in nuclear sharing has gained more serious consideration since the invasion and Russia’s announcement in March 2023 that it would engage in nuclear sharing with Belarus. Other proposals include developing and deploying new types of nuclear weapons and increasing the capacity of US non-strategic nuclear weapons in Europe to survive counterforce attacks. This essay argues that NATO should not increase reliance on weapons of mass destruction by augmenting its superior conventional forces. While sufficient defensive forces are needed, Europeans should avoid excess in the nuclear domain to avoid escalation and arms race dynamics and promote long-term solutions to the continent’s security challenges.
Non-strategic nuclear weapons were initially deployed in Europe in the 1950s to offset Soviet superiority in conventional military power and assure allies of the USA’s commitment to their defense. These weapons are designed for tactical use on the battlefield or in the theatre of war, reflecting the Soviet/Russian-US relationship. NATO strategists believed that lowering the threshold for nuclear weapon use would make the alliance’s deterrent threats more credible and potentially more effective in preventing Soviet conventional aggression. The logic of escalation control posits that NATO’s use of non-strategic nuclear weapons could deter the Soviet Union from responding, or limit or even win the nuclear war.
The escalation control logic for nuclear weapons in Europe is based on shaky assumptions, as the first use of a nuclear weapon does not necessarily trigger a nuclear response. After the end of the cold war, NATO’s power shift led to a reduction in non-strategic nuclear weapons deployed on Europe, with only air-deliverable B-61 bombs remaining. Greece and the UK ended their participation in nuclear sharing, and German officials proposed the same.
The significance of nuclear sharing was heightened by Russia’s 2014 annexation of Crimea and 2022 invasion of Ukraine, prompting the modernization of B-61 bombs and their delivery vehicles. This increased the role of non-strategic nuclear weapons, but did not create a new military rationale. NATO’s deterrent power is primarily due to its political unity and advanced conventional forces. The alliance’s strength has grown with the shift towards ‘forward defence’ and recent Nordic enlargement, particularly in the Baltic region where Russia is most likely to seize territory before mobilizing allied forces. The war in Ukraine has also shown that Russia’s precision-strike weapons are not as advanced as previously assumed.
The US strategic nuclear forces, including nuclear-armed submarines, long-range strategic bombers, and intercontinental missiles, hold Russia under existential threat at all times. NATO’s extended nuclear deterrence relies on these weapons, and the USA has intensified nuclear signalling since 2022, including increased overflights and strategic bomber landings near Russian borders.
However, the US non-strategic nuclear weapons under NATO nuclear sharing arrangements do not constitute a credible means of deterrence. The replacement of older DCA with F-35s increases the likelihood of penetrating adversary’s air defenses, but this would require authorization by the US and UK heads of state and consensus among the alliance’s Nuclear Planning Group. This would mean an unlikely agreement among 30 European democracies to order the first use of nuclear weapons or respond in kind to a nuclear strike, engaging in nuclear warfare.
The expansion of the existing nuclear sharing model to include new countries makes little sense as a means to strengthen deterrence. A new nuclear weapon base in Poland would add another location to the adversary’s nuclear war targets list, with US nuclear weapons contributing to deterrence largely derived from the American boots on the ground with the B-61 package.
NATO could designate several Polish airfields as potential Dispersed Operating Bases (DABs) to provide additional options for dispersing dual-capable aircraft in wartime and near-war situations. The report also suggests that Polish F-35s could be certified to deliver such weapons, and similar measures could be taken in other member states. Until now, only US allies that host nuclear weapons have been authorized to operate DCA under NATO nuclear sharing arrangements.
In the UK, some elements of a dispersal strategy are being implemented, with the nuclear weapon storage facility at RAF Lakenheath airbase being upgraded 15 years after the withdrawal of US non-strategic nuclear weapons from the UK. The report also points to construction projects at other hosting states’ nuclear weapon bases designed to facilitate the rapid movement of weapons on- and off-base to increase operational flexibility.
Depending on the extent to which the dispersal strategy is implemented, it would complicate targeting for the adversary by creating uncertainty about the location of NATO nuclear forces. However, Russia can be expected to hedge against this uncertainty by expanding the list of European targets during a hypothetical nuclear war to include potential rather than just known nuclear weapon facilities, exposing a bigger portion of the European continent to the devastating effects of nuclear explosions.
Calls for new nuclear weapons in Europe have been made, with some commentators arguing for the reintroduction of land-based intermediate-range missiles to Europe. These sub-strategic weapons, with a range of 500-5500 kilometers, were banned by the 1987 Intermediate-Range Nuclear Forces (INF) Treaty, from which both Russia and the USA withdrew in 2019. However, the prospects of recreating such circumstances today are slim, and European intermediate-range missile deployments would likely result in a reciprocal Russian response, further worsening regional arms race dynamics. The October report by the Congressional Commission on the Strategic Posture of the USA suggests the deployment, survival, and variability of additional theatre nuclear capabilities in Europe.
These could include land-based intermediate-range missiles and nuclear-armed sea-launched cruise missiles (SLCM-N). However, nuclear force build-up involving new nuclear weapons would be a hard sell in Europe, especially if new land-based missiles were introduced to the continent. Deployment of SLCM-Ns on US attack submarines would be less visible and thus less controversial among allied countries. However, it would pose a challenge for US relations and military cooperation with those NATO members (such as Denmark and Norway) that do not allow the transit of nuclear weapons through their territory or visits by nuclear-armed vessels at their ports.
Europe’s insecurity has led to increased reliance on nuclear weapons, as conventional deterrence is difficult to predict due to factors like strategy, tactics, and morale. This has led to underestimated NATO’s power compared to Russia. Russia’s nuclear threats have exposed Europe’s vulnerability for the first time since the end of the Cold War. US strategic signalling and plans to strengthen NATO’s non-strategic nuclear forces have reassured European allies, but they also contribute to the illusion that greater investment in nuclear deterrence could reduce vulnerability.
The downside to the prevailing power imbalance in Europe’s favor is that Russia will likely continue its greater reliance on nuclear weapons while it rebuilds its conventional forces. There is no military solution to this problem, and threat perceptions on both sides need to be addressed through the creation of a more sustainable regional security order that ensures sovereignty for Ukraine and other countries that might fall victim to Russian aggression.