Europe’s Nuclear Question: Deterrence, Dependency, and the Limits of Strategic Autonomy

The question of whether the European Union should pursue a nuclear deterrent has shifted, quietly but unmistakably, from mere academic speculation to strategic contingency planning. It is not reflected in official Council conclusions, but in ministerial corridors and think tank backchannels the issue is no longer treated as unthinkable. This is mainly due to the gradual loss of confidence in the security pillars that have kept Europe secure since the end of the Cold War.

At its core, the debate is driven by uncertainty over the long-term reliability of the United States’ extended deterrence. While NATO remains operationally intact, European policymakers, particularly in Berlin, Paris, and Warsaw, are increasingly factoring in scenarios where US political volatility translates into reduced nuclear guarantees. The Trump presidency first triggered this reassessment by showing how quickly Washington could take security decisions with major consequences for Europe without meaningful prior coordination, most notably through the US withdrawal from the JCPOA and the reimposition of secondary sanctions that directly affected European interests. More recent episodes have reinforced the point: in March 2026, Trump openly rebuked NATO allies after they refused to join a U.S.-backed operation in the Strait of Hormuz, warning of a “very bad” future for the alliance and underlining to many European capitals that consultation and strategic alignment can no longer be assumed automatically. The result is a slow but perceptible shift from strategic dependency to contingency autonomy.

In practical terms, however, an EU-level nuclear deterrent faces structural political and legal barriers. The EU treaties provide no competence in nuclear weapons policy, and any move in this direction would require unanimous treaty change, a highly unlikely prospect given the deep divergences among member states. Countries such as Austria and Ireland remain committed, as a matter of principle, to nuclear disarmament, while others, including Germany, are held back by a deeply embedded anti-nuclear political culture as well as constitutional sensitivities linked to the country’s post-war legal and strategic order. Even raising the issue publicly risks triggering internal fragmentation.

This leaves France as the only realistic anchor for any European nuclear dimension. Paris has, for years, signaled a conditional willingness to extend a European role around its nuclear deterrent, through Macron’s 2020 offer to engage European partners in a strategic dialogue on nuclear deterrence. But the French position has always been carefully limited: France is not offering to share control over its nuclear weapons, only to involve partners more closely at the political level, for example through consultations, joint exercises, or closer alignment in public messaging. In other words, France may be willing to make its deterrent more politically European, but not to give up national control over it.

From a strategic perspective, the key question is credibility. A deterrent is only effective if it is both capable and politically believable. An EU-branded nuclear force, if it were ever to exist, would struggle on both counts. Capability could, in theory, be assembled over time, either through French leadership or a Franco-British arrangement, even though the UK’s position outside the EU complicates this. Credibility, however, depends on decision-making clarity. Would 27 member states agree on nuclear use under crisis conditions? The historical record of EU foreign policy coordination suggests otherwise.

There is also a broader proliferation risk. An EU move toward nuclearization could weaken the global non-proliferation regime and provide justification for similar debates in other regions. European diplomats are acutely aware of this trade-off, particularly given the EU’s longstanding role as a champion of arms control frameworks.

In reality, the more plausible trajectory is incremental rather than transformative. This would mean closer integration of France’s deterrent into European strategic planning, broader formats for nuclear consultation, and greater investment in conventional military capabilities designed to make aggression harder to carry out successfully in the first place, rather than simply threatening retaliation after the fact. Discreetly, some officials are also exploring legal and financial mechanisms through which willing member states could support France’s nuclear posture without formalising an EU competence.

In sum, the EU is unlikely to become a nuclear power in its own right. But the fact that the question is now being asked seriously reveals a deeper shift: Europe is beginning to prepare for a world in which its security can no longer be outsourced.

Author(s):  Andrew Staniforth, SAHER Europe