Can Europe Build Its Own Nuclear Umbrella?
Deepening doubts about the reliability of the United States’ extended nuclear deterrence have pushed Europe to seriously consider an idea that was long considered almost unthinkable: building its own nuclear umbrella. These concerns have grown markedly in recent months. The stance of the current US administration toward NATO allies, questions over American willingness to defend Europe in a high-stakes crisis with Russia, and the expiration of the New START treaty have led many European capitals to question whether they can continue to fully rely on Washington’s nuclear guarantee.
France has responded with a significant doctrinal evolution. In his speech of 2 March 2026 at the Île Longue submarine base, President Emmanuel Macron introduced the concept of “forward deterrence” (dissuasion avancée), confirmed that France’s vital interests have a clear European dimension, announced an increase in the size of the French nuclear arsenal, and signalled greater openness to nuclear cooperation and strategic dialogue with European partners. These developments come on top of the July 2025 Northwood Declaration between France and the United Kingdom, which substantially strengthened bilateral nuclear coordination.
The central question this discussion addresses is: Can France and the United Kingdom provide a credible nuclear umbrella for Europe, either as a complement to or a potential replacement for the American one? Would such an arrangement strengthen deterrence vis-à-vis Russia, or would it introduce new strategic risks?
Pavel Podvig and William Alberque will offer sharply contrasting assessments of this critical issue.
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Pavel Podvig
Researcher at Russian Nuclear Forces Project
William Alberque
Senior Adjunct Fellow at The Pacific Forum
William Alberque: The Umbrellas of Luxembourg: Can Europe Deter Russia?
The question posed by StarkTalk to Pavel Podvig was “would France or the United Kingdom be able to replace the United States in providing a nuclear umbrella for Europe?” His answer is “no”, but I do not find his answer persuasive. His answer mentions the UK only once, focusing instead on France’s inability to provide credible extended deterrence guarantees, while also questioning US extended deterrence. While he admits that the US promise of extended deterrence remains “somewhat plausible,” he casts doubt on the ability of nuclear deterrence to prevent anything other than direct aggression.
Leaving aside doubts on the efficacy of nuclear deterrence overall and extended deterrence as a subset thereof, I will focus instead on how the UK can lead UK-French nuclear cooperation to provide NATO with a stronger European leg of the nuclear deterrent. If they follow my recommendations, UK and France can enhance deterrence against Russia both in coordination with and in the absence of a US extended nuclear deterrence guarantee. While there are political, technical, and financial problems to be overcome, I believe this also reduces potential escalation risks by building a stronger European stake in deterrence – not on the same level as in the Cold War, but stronger than what has existed in Europe for 30 years.
Lancaster 2.0: Help is on the Way
On 10 July, Prime Minister Kier Starmer and President Emmanuel Macron signed the “Northwood Declaration”, deepening and expanding UK-French defence cooperation on areas including on nuclear weapons and nuclear policy coordination, as well as joint development of deep-strike capabilities. The Northwood Declaration builds on the UK Strategic Defence Review, wherein the Starmer Government pledged to improve the UK nuclear deterrent, as well as the Lancaster House Treaties of 2010.
Starmer also announced at the NATO Summit in the Hague the restoration of the nuclear mission to the Royal Air Force, including the purchase of at least 12 nuclear-capable F-35As to rejoin the NATO Dual Capable Aircraft Mission (DCA) – that is, their ability to deliver US tactical nuclear weapons – and an expansion of the UK nuclear-powered attack submarine (SSN) fleet from 7 to 12 subs through the AUKUS programme – to protect the nuclear-powered ballistic missile submarine (SSBN) fleet as well as UK sea lines of communication in the North Atlantic into the Pacific. This former change was first reported on 1 June in the Times of London and connects to the US restoration of its B-61 nuclear bomb storage facilities at RAF Lakenheath, and the latter change was described more fully in the SDR.
The Lancaster Treaties of 2010 include joint work on nuclear stockpile stewardship through experiments at the France-UK joint facility EPURE in Valduc, France. The Lancaster Treaties were improved in 2014 under the Declaration on Security and Defence, which includes peer review and joint experiments outside of nuclear warheads. The UK has been contemplating increasing its nuclear warhead totals, dating back to the 2021 SDSR wherein they raised the warhead ceiling for the UK arsenal.
Diversification as a hedge on nuclear dependency risks
Now, under Northwood, the UK and France can expand joint work to include new nuclear warhead designs –both are developing new warheads for their SLBM fleet, and France is building a new warhead for their next-generation nuclear-armed air launched cruise missile (ALCM-N) known as the AS4NG. The current UK nuclear arsenal warheads comprises of a US design – the Holbrook warhead, carried by Vanguard submarines and delivered by US-built Trident II D-5s missiles. There is good reason now for both the SLBM warhead and the ALCM-N warhead, not to mention both types of missiles, to be jointly developed and produced, although for different roles based on differing doctrine. The UK can reduce its dependence on the US for critical warhead components, for instance, through access to French-produced tritium. Northwood also establishes a new nuclear consultation committee, called the UK-France Steering Group, which is mandated to “coordinate across nuclear policy, capabilities, and operations.”
While nuclear sharing by the US with the Royal Air Force increases UK nuclear dependence on the US in the short term, it provides a path to longer-term strategic independence through catalytic learning capabilities. UK participation in nuclear sharing is a relatively fast and inexpensive pathway to the re-introduction the culture of nuclear safety and handling, and tactical nuclear planning, targeting, and delivery outside of the Royal Navy Submarine Service and into the whole of the UK Armed Forces.
France is limited in its extended deterrence guarantees both doctrinally – it sees its SLBMs and ALCM-Ns as for strategic deterrence only – and because it refuses to allow other countries to participate in joint nuclear planning, decision-making, or delivery. Macron has heavily trailed a new speech on nuclear doctrine in the new year, which may increase the role for European contributions, but it is unlikely to shift towards a reliable extended deterrence guarantee such as the US provides.
The UK, however, has no doctrinal impediment to offering ALCM-Ns to NATO DCA as a supplement (or, in extremis, a replacement) to the US B61s dedicated to NATO. Also, while France historically has refused external funding for its nuclear arsenal, the UK offered NATO air- and sea-delivered nuclear systems under joint funding in its Atlantic Nuclear Force offer of 1965. Thus, the UK could look to NATO Allies to expand UK nuclear warhead manufacture capability based on joint France-UK designs for ALCMs and SLBMs, and Allies could purchase a UK-French designed AS4NG, which would be designed to be compatible with all NATO 4th and 5th generation fighters for maximum flexibility. The UK also could expand its SSBN fleet through common funding, including more warheads and SLBMs to be uploaded to the new Vanguard Class boats.
Conclusion
Thus, the UK and France could offer both more strategic and theater nuclear systems to provide more and stronger NATO deterrence options – whether the US chooses to disengage or remain the cornerstone of NATO’s nuclear deterrent. Would this be enough to deter Russia? I believe it would – as, to push back on Pavel’s argument, France would see the loss of any NATO territory as a direct threat to its own security interests, and destroy the Alliance itself. France remains traumatized by its experience in the Second World War, and is unlikely to allow Russia to seize more and more NATO territory. It retains an interest in deterring Russia at NATO’s frontlines. I believe therefore that increasing French and UK warheads and delivery platforms with UK nuclear sharing should be sufficient to deter Russia in the future.
- William Alberque
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Wolfgang Hierse
Managing Partner at G-SAM GmbH
I believe we can agree that there is currently no credible nuclear deterrence covering the East European countries. I believe we can also agree that Russia's objectives behind the current war are not limited to Ukraine. The goal is a broader pushback against NATO in Eastern Europe, as evidenced by Russia's ultimatums directly before the attack on Ukraine. Still, Russia prefers to attack Ukraine - a non-member of NATO - and not the Eastern member states of NATO, which would be the more logical war target. So, some deterrence seems to be in effect against Russia, and it is not nuclear at this point. Isn't this evidence that Europe doesn't need nuclear armament to deter Russia?
Answered
William Alberque
I agree with you - mostly. Russia's clear goal is to create a boundary made of buffer states with limited sovereignty, and yet has not invaded, for example, the Baltics to create such a boundary. It also would love to end the NATO Alliance, and any successful attack on a NATO state without retribution would fulfill that goal. At the same time, Russia has felt free to occupy part of Moldova, invade Georgia, and invade Ukraine.
You would be right to conclude, therefore, that Russia has been successfully deterred by NATO from attacking NATO territory. It is important to note the role that NATO nuclear deterrence - supplied by the US and UK deterrent and supported by French nuclear weapons independently, is an irreducible part of NATO's deterrence.
I agree that additional European states should not acquire nuclear weapons - rather, as I've argued, the UK should step up in this regard to provide additional deterrence while avoiding actual nuclear proliferation among Allies. Further proliferation likely would end the NPT and have a terrible knock-on effect on global security, despite any short-term gains by proliferating.
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Alex Kolbin
Consultant at Independent
By asking "whether France or the UK can replace US extended deterrence", we already admit that the US extended deterrence is either incomplete or unreliable. That was mentioned in the introductory text as well, so I suppose everyone agrees on that. and the more precise question is whether France and UK can (need?) substitute something that is already ineffective? So here, the answer is probably yes, they can.
The deeper question, which, I think, was also addressed by Pavel, is whether nuclear deterrence as a concept still works in today’s environment. For example, Ukraine can receive precision strike capabilities that cover a very large share of Russia’s population, infrastructure and strategic depth, so Moscow’s deterrence is clearly not preventing Europe )NATO) from crossing thresholds that once looked untouchable. Current security environment suggests Europe may need less faith in old (also US-originated) strategic formulas and more investment in real (effective) tools of deterrence: precision strike, air and missile defence, AI, mobilisation, and the political will to absorb risk (the way Putin's Russia did so far). That's where today's deterrence lies, I think. Thus, another important question may be what set of non-nuclear capabilities can make nuclear coercion less effective?
Pavel Podvig
Researcher at Russian Nuclear Forces Project
I would agree with William that France and the United Kingdom can do quite a bit, even though many of these steps, like the development of a new warhead, not to mention the construction of submarines, are likely to take a very long time. The question, however, is not whether this is possible, but whether this would help. I don't think one can "[leave] aside doubts on the efficacy of nuclear deterrence overall and extended deterrence as a subset thereof" in answering this question. Yes, France was traumatized by its experience in the Second World War, but would that be enough to risk serious damage to France in an attempt to prevent Russia from seizing some NATO territory? I don't see a scenario in which it would be. If the argument is that a more diverse nuclear arsenal, with ALCM-N and similar weapons, would help keep a nuclear exchange "over there," away from France's (or UK's) territory, then it is also not clear how this would help repel an aggression. France and the UK would have every incentive to keep the conflict away, even at the cost of ending the conflict on unfavorable terms. It's not a question of warhead designs or policy coordination. It's a structural problem that cannot be simply left aside.
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