As doubts grow over US reliability, the French president is set to unveil his plans at a nuclear submarine base in Brittany, proposing closer cooperation with allies while insisting ultimate control will remain in Paris.
French President Emmanuel Macron is expected to rule out any form of shared European control over France’s nuclear arsenal – while clarifying what Paris can offer allies who have doubts over the reliability of the United States’ nuclear umbrella under President Donald Trump.
Speaking on Monday at France’s Île Longue nuclear submarine base in Brittany, the French president is set to outline what aides have described as “fairly significant shifts and developments” in the country’s nuclear doctrine.
For decades, Europe’s security architecture has rested firmly on American guarantees. While France and Britain maintain independent nuclear arsenals, most European nations rely on Washington as the ultimate deterrent.
But recent geopolitical shifts, from Trump’s warmer tone towards Russia over Ukraine to sharper rhetoric directed at traditional allies, have prompted a rethink in capitals across the continent.
Macron has already suggested possible avenues for closer cooperation, including joint exercises, “shared security interests” with key partners, and even the potential deployment of French nuclear-capable aircraft in other European countries.
Germany has opened discussions with France on the possibility of a European nuclear deterrent, while Britain has signalled it is seeking to deepen nuclear cooperation with Paris. Some Nordic countries have also shown cautious interest.
Macron himself has framed the debate as part of a broader, more “holistic” approach to European defence and security.
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Questions over capability
However, some European officials have privately questioned whether France’s nuclear arsenal – estimated at around 290 warheads – could credibly extend protection across the continent.
The questions are not just over scale, but structure too: who would pay, who would decide and how would such a system fit alongside existing NATO arrangements?
France currently spends €5.6 billion annually maintaining its deterrent. Expanding its role would require significant additional investment, at a time when many governments are struggling to boost conventional military capabilities.
Analysts argue that any future European deterrent built around French and British forces would need to grow in size or adapt its composition to remain credible.
NATO secretary-general Mark Rutte has warned that any attempt by Europe to go it alone would come at enormous cost, potentially weakening rather than strengthening overall security.
The United States, for its part, continues to station around 100 nuclear bombs across several European countries under NATO’s nuclear sharing arrangements – a strategy that remains central to collective defence, despite reassurances from Washington doing little to calm fears of unpredictability under Trump.
French officials are keen to stress that Paris is not seeking to replace the US umbrella. Rather, its doctrine is built on a different philosophy: not matching adversaries weapon for weapon, but maintaining a smaller force capable of inflicting unacceptable damage on key political, military and economic targets.
In theory, this approach requires fewer warheads to remain credible. Still, some allies remain unconvinced.
For eastern European states in particular, credibility is everything – and strategic ambiguity, long a cornerstone of France’s doctrine, can feel more unsettling than reassuring.
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France’s line in the sand
At the heart of Macron’s update is an effort to clarify what France’s deterrent can, and cannot, do for Europe.
Paris has drawn a firm line on one point: its nuclear forces will remain under exclusive national control, funded solely by France and ultimately commanded by the French president.
Senior French officials and former advisers have underlined that any form of shared launch authority would undermine credibility. “I can’t see us having 27 buttons,” former presidential military adviser Bernard Rogel said, reflecting concerns about decision-making across the European Union.
That position reflects a longstanding principle. While France has hinted that its “vital interests” extend beyond its own borders to include a European dimension, it has never committed to formal guarantees akin to those provided by the US.
Another key challenge lies in capability. Any meaningful expansion of Europe’s deterrence would likely require advanced deep-strike missile systems with ranges exceeding 2,000 kilometres – technology that Europe currently lacks.
Developing tactical nuclear weapons for battlefield use is seen as even less likely, given the political and legal sensitivities surrounding nuclear proliferation.
There is also a broader concern that increasing the number of nuclear weapons worldwide would ultimately make the world less safe. European Union foreign policy chief Kaja Kallas has voiced this unease, reflecting a wider tension between the desire for stronger deterrence and the long-standing commitment to arms control.
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Macron’s speech comes at a moment of change. Since his last doctrine update in 2020, Russia has expanded its nuclear arsenal and sharpened its rhetoric, particularly following its full-scale invasion of Ukraine in 2022.
The debate is also gaining traction among European publics, with growing support in several countries for strengthening a shared deterrent.
Still, the political risks remain high. With domestic tensions rising ahead of France’s 2027 presidential election, analysts warn that any move towards a more explicitly “European” nuclear posture could prove controversial at home.
The act of debating alternatives to the US umbrella in itself carries symbolic weight. European officials say it sends a signal to Moscow that the continent is taking its security more seriously – even if practical changes remain limited for now.
(with newswires)
