Political Will, Not Just Military Capabilities
Nuclear weapons in Europe are, and will remain, the sovereign responsibility of two individual states, France and the United Kingdom. It is common knowledge that the United Kingdom contributes to NATO’s deterrence and defence as a member of the Nuclear Planning Group, while France does not. Nevertheless, various European nuclear projects have been proposed by France since the 1950s. The most prominent example is President Macron’s speech in January 2024 at the Swedish Defence University, where he stated that “French vital interests have a European dimension.” However, as early as 1995, President Chirac put forward the concept of “concerted deterrence.” Similar to Macron, Chirac invited European allies to cooperate on European deterrence.
It is true that France’s absence from NATO’s Nuclear Planning Group is an institutional limitation, but it is hardly insurmountable. France has already demonstrated a willingness to adapt its NATO engagement in the past by rejoining NATO’s integrated military command structure in 2009. If the need arises, it is a credible possibility that they will join the NPG, especially if it is no longer under US leadership. Furthermore, the structure of a European deterrent does not need to be identical to NATO’s existing model or even within a NATO framework. It is imaginable that European allies develop a novel consultation mechanism similar to NATO’s Nuclear Planning Group either as its own format or under the European Union’s umbrella. Nevertheless, NATO expertise, procedures, and infrastructure would be invaluable for any future arrangement and offer credibility based on path dependency.
It is often argued that American commitment is misjudged and that, in reality, the bipartisan support for NATO and extended nuclear deterrence is steadfast. This might be the case, or it might not. But certainty is equally essential for nuclear deterrence as credibility and capabilities are. Due to the unpredictability of the current US administration, the resolve of the United States is as ambiguous as French doctrine. Domestic political instability is a valid concern for extended deterrence, be it by France or the United States. Political will is never guaranteed. But doctrines can evolve as well. The point is not to build a flawless system, but a credible and adaptive one.
While there is no unified European nuclear arsenal, this does not preclude the development of a more formalised collective nuclear deterrence posture. Currently, France and the United Kingdom do not offer extended deterrence like the United States does. But this can change. A framework in which France and the UK explicitly extend their nuclear umbrellas to European allies, through doctrine, joint exercises, and nuclear sharing arrangements, would not only strengthen deterrence itself but also provide an urgently needed political signal of European resolve. Of course, the fundamental commitment issue of extended deterrence remains: would a state really sacrifice one of its own cities for the sake of an ally? The answer becomes less abstract when the trade-off is “Paris-for-Berlin” or “London-for-Warsaw,” rather than “New York-for-Paris.” The psychological and political calculus shifts dramatically when nuclear escalation unfolds on one’s own continent. The proximity of European capitals geographically, but also politically and socially, means that any nuclear aggression would inevitably affect all of Europe, regardless of initial targets. Therefore, extended deterrence offered by a European state will inherently be more credible than anything the United States can offer.
The Curse of Geography
As President Macron rightly noted, it is unimaginable that a threat to one European ally would not also be a threat to France, or the United Kingdom. This is not a rhetorical figure but a geographic reality. Unlike the United States, Europe is compact and densely interconnected. A nuclear strike anywhere in Europe would have political, environmental, and humanitarian consequences across borders. In this context, European extended deterrence should be considered significantly more credible than what the United States offers.
Additionally, the close proximity makes lower-yield or “tactical” nuclear war not merely undesirable, but strategically suicidal. Europe cannot afford to fight a nuclear war on its own soil. This makes the development of a distinctly European nuclear doctrine essential. While such a doctrine does not yet exist, the debate must begin. It should be shaped by a clear rejection of nuclear warfighting and guided by the need for credible deterrence through the threat of unacceptable retaliation. The shared geography, history, and increasing sense of political identity among Europeans, despite all internal disagreements, provide a basis for this doctrine that is stronger than outside observers often assume.
Capabilities and Credibility
The often-invoked distinction between tactical and strategic weapons also obscures more than it reveals. A weapon’s impact depends on its use and context, not just its range or yield. It is questionable whether Russia is likely to escalate less merely because a lower-yield device is used to target a strategic vulnerability. Once a nuclear threshold is crossed, the dynamics of escalation become dangerously unpredictable. In such a scenario, a French “warning shot” could in fact be a more credible tool for signalling resolve and managing escalation than the existing US lower-yield nuclear weapons forward deployed in Europe. Furthermore, even after the recent completion of their Life Extension Program, systems such as the outdated B-61s have little to no real utility today, especially in warfighting. As General Cartwright already noted in 2012: “[the B61 nuclear bombs] military utility is practically nil. They do not have assigned missions as part of any war plan and remain deployed today only for political reasons within the NATO alliance.” For this reason, and the previously established argument that Europe should have no interest in nuclear warfighting, the argument that only the United States’ lower-yield nuclear weapons can guarantee a proportionate response should be rejected.
Sceptics rightly point to the UK’s technical dependence on the United States and the absence of a full nuclear triad in either British or French forces. These are undoubtedly important limitations. But nuclear deterrence is not a numbers game. No one questions North Korea’s resolve because of its smaller arsenal. And China, despite possessing far fewer warheads, raises serious strategic concerns in Washington. Credibility is not about symmetry; it is about the assured ability and political will to impose unacceptable costs. Whether hundreds or thousands of nuclear weapons are necessary to achieve more deterrent value is not really the central question. Russia has relatively few population and military centres of strategic value, and the combined existing European arsenals have more than sufficient capabilities to threaten them numerically. That said, modernisation and expansion, particularly in the form of mobile land-based missiles and nuclear submarines, would significantly bolster deterrence. In the face of the limited number of European nuclear weapons, an assured second-strike capability is crucial. Investments in survivability are imperative. The United Kingdom’s decision to procure F-35As capable of carrying nuclear weapons is a step in the right direction. It improves capabilities and shows resolve. Most importantly, it reflects the acknowledgement of a new threat environment and highlights that European states are willing to adapt their capabilities, policies, and doctrines.
Conventional Deterrence Still Comes First
To be clear, nuclear deterrence is only part of the equation. Europe’s first and most immediate defence priority must be a stronger conventional posture, particularly deep strike capabilities which can have strategic effects comparable to nuclear weapons in degrading adversary capabilities and deterrence. Conventional deterrence and defence capability are crucial for preventing conflict reaching the nuclear threshold. Furthermore, strong conventional deep strike capabilities could be used for flexible and tailored response options as an alternative to lower-yield nuclear weapons. The most likely Russian strategy in a confrontation will be to achieve a fait accompli in the Baltic, followed by nuclear blackmail to break NATO allies’ resolve and disunite the alliance, possibly accompanied by conventional long-range strikes. In this scenario, the use of lower-yield nuclear weapons by a NATO ally is highly unlikely.
Concluding Thoughts
The paradox of nuclear deterrence is that it aims to prevent the very war it prepares for. In Europe’s case, the path to preventing nuclear war may lie in taking greater responsibility for its own nuclear deterrence. This does not mean duplicating the United States arsenal or decoupling from NATO. Every effort should be undertaken to prevent nuclear war, and all Europeans should hope that the United States remains a close partner. Nevertheless, to take on greater responsibility means building a more European framework that is credible, connected, and resilient. The “New York-for-Paris Dilemma” remains, but can be mitigated by a “Paris-for-Berlin” approach, which is more credible due to geographic proximity and a shared European identity. Deterrence, after all, is socially constructed both in the mind of the derring and the deterred. Its success depends as much on political will and strategic signalling as on technical capabilities. Europe must not talk itself out of deterring. With the right vision and cooperation, a stronger European deterrent posture is not only necessary but also feasible.