Recently, the US announced the withdrawal of 5,000 troops from Germany (around 14 per cent of US forces stationed in the country). Although the move comes after German Chancellor Friedrich Merz said the US was being “humiliated” by Iran and questioned its strategy in the conflict, it is also seen as reinforcing growing uncertainty in the transatlantic security partnership.Notably, French President Emmanuel Macron appeared to anticipate this moment while speaking at the Île Longue ballistic missile submarine (SSBN) base in Brittany in northwestern France on March 2. Speaking with a French navy nuclear-armed submarine, le Téméraire, as a backdrop, Macron outlined the idea of “dissuasion avancée” (forward deterrence), a French-led nuclear framework for European security. It is widely seen as the most significant speech by a European leader in the last three decades on nuclear deterrence, as it signalled a push towards rethinking Europe’s dependence on the US-led nuclear umbrella. Before comprehending the term nuclear umbrella, let’s briefly examine the major factors pushing Europe to the brink. Why is Europe reviewing its security? Several factors have driven this reconsideration – from the weakening of trust in the credibility of the US commitment to Europe’s security to heightened rhetoric from Russia, and the resurgence of China. US commitment to Europe’s security: The credibility of the US commitment to Europe’s security has weakened considerably. The Trump administration’s transactional approach to the North Atlantic Treaty Organization (NATO), along with troop withdrawals, has created serious doubts about Washington’s role as Europe’s primary security guarantor. Russia’s nuclear arms threat: Alongside the nuclear arms threat, Moscow has deployed nuclear weapons on NATO’s eastern border in Belarus. Furthermore, the erosion of major arms control frameworks, including the collapse of the Intermediate-Range Nuclear Forces Treaty (INF), the weakening of the New START treaty, and Russia’s withdrawal of the country’s ratification of the 1996 Comprehensive Test Ban Treaty (CTBT), has further compounded security concerns in Europe. Story continues below this adEmergence of China as a strategic competitor: The rise of China as a strategic competitor and a major arms producer has further shifted the US attention, raising concerns in Europe about a gradual shift in US priorities away from the transatlantic alliance. Together, these developments have reinforced debates in Europe over strategic autonomy – the idea that Europe should be able to ensure its own security without excessive dependence on external powers, which also includes taking more responsibility for its own deterrence. Against this backdrop, attention has been redrawn to the nuclear umbrella that has underpinned European security since the 1940s. What is a nuclear umbrella? Since the late 1940s, European security has relied on what is known as a nuclear umbrella. In simple terms, it is a security guarantee by a nuclear-armed state to protect an allied non-nuclear state. It is a form of ‘extended deterrence’ that seeks to convince adversaries that any attack on allied states would invite retaliation, thereby raising the cost of aggression. This is not limited to Europe, but also includes US security alliances with Japan and South Korea, where Washington commits to their defence under its nuclear deterrent. The non-nuclear states under protection are often described as umbrella states, as they are protected under the nuclear capabilities of another state. Story continues below this adNotably, the nuclear umbrella has been a core tool of non-proliferation policy because it reduces the chances of protected states to building their own nuclear weapons. How does it work in Europe?In Europe, the nuclear umbrella primarily operates through NATO. The US extends its nuclear deterrence to its European allies under the collective defence principle enshrined in Article 5 of the NATO treaty, where an armed attack on one member is considered an attack on all. As per NATO’s nuclear sharing arrangements, the US deploys nuclear weapons (mainly B61 bombs) at bases in five NATO countries – Germany, Belgium, the Netherlands, Italy, and Turkey. These weapons remain under US control in peacetime. At the same time, allied nations maintain dual-capable aircraft with trained pilots to deliver the weapons during a crisis. This system operates under a dual-key arrangement, requiring authorisation from both the US and the host nation for the delivery of the weapon. Story continues below this adNuclear policy and planning among allies are coordinated through NATO’s Nuclear Planning Group. However, since the ultimate authority over the use of nuclear weapons rests with the US President, European states are increasingly reconsidering the long-term credibility of these arrangements. How does Europe seek to strengthen its deterrence? Against this backdrop, European states have responded on multiple fronts. On conventional defence, many European countries are now spending at or above NATO’s 2 per cent of GDP on defence.They are also expanding their military capabilities and accelerating investment in air defence, long-range missiles, and early warning systems. Germany’s historic Zeitenwende (turning point) policy exemplifies this shift through its €100 billion special defence fund aimed at modernising its armed forces. At the nuclear level, France and the UK – the only European countries with independent nuclear deterrents – are modernising their arsenals and deepening cooperation. The 2025 Northwood Declaration committed both countries to greater coordination on nuclear deterrence and strategic cooperation.Story continues below this adAlthough significant, the initiative remains outside the institutional framework of the European Union. Macron’s “forward deterrence” proposal represents the most ambitious effort to build on this foundation. What is “forward deterrence”?Macron’s initiative seeks to develop a unique European approach to deterrence. It rests on five key elements. * First, France would engage with European partners on issues concerning nuclear deterrence and crisis signalling, including through the newly established nuclear steering group with Germany. * Second, the participation of allies in French nuclear exercises. * Third, temporary deployment of French air assets on the territory of European partners.Story continues below this ad* Fourth, further investment in conventional capabilities, including early air warning systems, new-generation surface-to-air missile systems, and long-range missile projects.* Fifth, an increase in its nuclear arsenal while maintaining strategic ambiguity by withholding the exact size. Importantly, Macron placed this initiative not as an alternative to NATO’s nuclear umbrella but as a complement to it. Several European partners, including Germany, Belgium, and the Netherlands, which also host US nuclear weapons, supported this proposal, further suggesting that it offers a fallback option for European countries amid uncertainties over US commitments. What are the challenges? Despite growing debate around European deterrence, Macron’s proposal faces challenges. For instance, France does not offer a formal collective guarantee similar to NATO’s nuclear umbrella. Decision regarding the use of nuclear weapons and their planning remains exclusively under French control. Story continues below this adEuropean nuclear deterrence also remains primarily Franco-British, with France and Britain the only states with independent nuclear deterrence and operational capabilities in Europe. While both countries have expanded strategic and nuclear cooperation, these efforts remain primarily bilateral. Moreover, European states continue to differ in their threat perceptions, while some still view the US as a guarantor of the continent’s security. France’s forward deterrence proposal marks an important shift in Europe’s security debate by moving discussions on European deterrence to concrete initiatives. Though it does not offer a viable alternative to the US-led nuclear umbrella, it represents a shift towards a distinctive European approach to nuclear deterrence. The future of European deterrence will depend on broader participation by European states, sustained Franco-British cooperation, and Europe’s ability to build political consensus on security and deterrence in an increasingly uncertain geopolitical environment. Post read questionsWhy is Europe reconsidering its dependence on the US-led nuclear umbrella? Examine the strategic factors behind this shift.Story continues below this adWhat is a nuclear umbrella? Discuss its role in maintaining European security since the Cold War.Discuss the significance of France’s “Forward Deterrence” proposal in the context of Europe’s quest for strategic autonomy.How has the changing global strategic environment revived debates on European strategic autonomy? Analyse.The credibility of extended nuclear deterrence depends as much on political trust as on military capability. Discuss in the context of NATO and Europe.(Pranjal Kashyap is a PhD candidate at the Centre for European Studies, Jawaharlal Nehru University, New Delhi.) Share your thoughts and ideas on UPSC Special articles with ashiya.parveen@indianexpress.com.Gear up for UPSC Prelims 2026—Practice smarter, revise faster, and succeed with our Special Quiz Magazine. (Click Here)Click Here to read the UPSC Essentials magazine for May 2026. 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