“The leading NATO countries are making aggressive statements regarding our country. Therefore, I order that Russia’s deterrence forces be placed on a special combat alert regime.” On 27 February 2022, Vladimir Putin moved beyond threats and into action. Three days after launching his invasion of Ukraine, he ordered Russia’s nuclear forces onto heightened alert. The scene was chilling, almost surreal. Seated apart from his military chiefs in a gilded hall, he turned nuclear weapons into an explicit instrument of coercion. The bomb was no longer merely a deterrent; it became a shield for aggression.

A Turning Point and the Wake-Up Call

A few months later, Joe Biden put those concerns into words. On 6 October 2022, he warned of the risk of “Armageddon” — the first such warning since the Cuban Missile Crisis of 1962. The conclusion, echoed in France’s National Strategic Review, was clear: the nuclear order was fragmenting and increasingly shaped by a multipolar system marked by competition between major powers.

This growing instability was driven not only by Russia’s increasingly aggressive efforts to deter outside intervention, but also by an unprecedented acceleration in the modernisation and expansion of nuclear arsenals.

Russia is undertaking a nuclear modernisation programme that goes far beyond simply renewing its strategic triad. Meanwhile, China is rapidly expanding its arsenal, which could reach 1,500 warheads by 2035, while remaining highly opaque about both its ambitions and how it intends to achieve them. Iran, now engaged in a cycle of open conflict in the Middle East, had previously crossed critical enrichment thresholds, casting a nuclear shadow over the region. At the same time, Europe is coming to recognise that it can no longer rely entirely on an ally whose priorities appear increasingly centred on the Indo-Pacific — and even on a more inward-looking posture.

A New Asset: Forward Deterrence

On 2 March 2026, against a backdrop of mounting strategic uncertainty, President Emmanuel Macron delivered a grave and solemn speech at Île Longue. The setting was symbolic: Île Longue, the granite stronghold that houses France’s nuclear ballistic missile submarines (SSBNs), the hidden cornerstone of its nuclear deterrent. Standing before a 140-metre steel giant, the President posed a crucial question: “Can we really imagine the survival of our closest partners being put at risk without that affecting our vital interests?” Behind this question lay a simple but decisive argument: in a world in which France’s interests are increasingly exposed, its security can no longer be considered in isolation. The President was building on a long-established principle, recalling that France’s vital interests have long had a European dimension, even if that dimension has never been explicitly defined. The ambiguity is deliberate. As he himself noted, “our red lines are not visible”, preserving the uncertainty on which deterrence depends. Yet the 2026 speech marked a turning point. It did more than acknowledge the European dimension of France’s vital interests — it translated it into action.

France has thus entered the era of forward deterrence. In practical terms, this means extending France’s strategic thinking beyond the defence of its national territory alone. It does not involve sharing nuclear weapons or diluting decision-making authority, which remains exclusively national. Rather, it reflects the increasingly tangible European dimension of France’s vital interests. Put simply, a major threat to certain European partners can now be integrated into France’s strategic assessments. This shift is also being translated into practical measures. Forward deterrence will be implemented gradually, with options tailored to each partner. These may include joint exercises, strategic signalling beyond France’s borders, the participation of allied conventional forces in French nuclear activities, and, ultimately, the deployment of elements of France’s strategic forces on allied territory when circumstances require.

Against this backdrop, existing partnerships are being deepened. Cooperation with the United Kingdom, an independent nuclear power, is rooted in a long-standing convergence of vital interests and was further strengthened in 2010 through a unique scientific partnership. At the same time, several European countries — including Germany, Poland, Sweden, Denmark, Greece, the Netherlands and Belgium — have agreed to join an in-depth strategic dialogue with France.

Built for a Clash of Wills

France’s nuclear deterrent is more than a feat of engineering. Above all, it is an intellectual construct: a strategic architecture designed to withstand crises and periods of profound international upheaval. It is underpinned by a rigorous set of principles that combine to form a coherent and credible system whose logic is clear to any potential adversary. At the heart of this architecture lies a fundamental paradox: France forges thunderbolts so that it will never have to use them. Nuclear weapons are not instruments of war; they are our most powerful means of preventing one. As François Mitterrand once said: “The purpose of deterrence is to prevent war. A potential aggressor must know that he stands to lose far more than he could ever hope to gain.”

The President of the Republic alone takes the decision, without sharing his authority or being subject to any form of control. This is the purest expression of the Gaullist legacy: the survival of a nation cannot be delegated. It is subject to no committee, no ally and no veto. This absolute sovereignty is the condition of our credibility.

An adversary must know that between the threat and the response stands a single decision-maker, able to act immediately and in full sovereignty. Yet France has always rejected the excesses of vast nuclear arsenals, preferring instead to maintain its capabilities at a strict level of sufficiency. Its objective is neither to possess more weapons than others nor to match them weapon for weapon, but simply to have enough to destroy what an adversary values most — what it considers vital. Deterrence is therefore less a game of numbers than a delicate balance between certainty and uncertainty: uncertainty about the precise circumstances in which a French President might decide to employ nuclear weapons, and certainty that no defence, however sophisticated, can shield an aggressor from French retaliation. Part of that certainty lies in the depths of the sea.

Since 1972, the heart of France’s deterrent has maintained a continuous presence beneath the waves. Somewhere in the vastness of the ocean, a ballistic missile submarine patrols unseen and undetected. Its mission is simple, yet decisive: to guarantee France’s ability to respond, whatever the circumstances. This is the principle of the second strike. In other words, even in the extreme event of a first strike against French territory, France would still retain the means to retaliate. Hidden in the depths, the submarine remains beyond the reach of any pre-emptive attack. France’s airborne nuclear component also maintains a permanent posture through the Strategic Air Forces (FAS), a mission they have fulfilled since 1964. Their response time can likewise be reduced to just a few minutes, allowing the entire force to be launched before an adversary could attempt to neutralise France’s deterrent in a single strike.

Whatever the Circumstances

The robustness of these two permanent components ensures that retaliation remains inevitable. Yet French doctrine is not confined to an “all-or-nothing” approach. Between inaction and a massive strike, it allows the President of the Republic to progressively adjust the posture of the nuclear forces, removing any ambiguity about France’s determination to defend itself. The available options include deploying two additional ballistic missile submarines, suspending Rafale and MRTT (Multi-Role Tanker Transport) training flights, initiating preventive maintenance to maximise availability, arming aircraft first with conventional and then nuclear weapons, and ultimately carrying out deployments before any overt increase in the level of alert.

Finally, should an adversary continue to threaten France’s vital interests, the doctrine provides for a final warning. Before crossing the threshold into the irreparable, France may resort to what is known as a nuclear warning. This does not mean waging nuclear war. Rather, it is a means of sending a clear message: the adversary has crossed a critical line. In practical terms, such a warning would take the form of a nuclear strike intended, in the words of François Hollande, to “restore deterrence by signalling that the red line has been crossed.” Second-strike capability, the ability to demonstrate France’s resolve through adjustments to its nuclear posture, and the nuclear warning itself together form a coherent whole guided by a single objective: convincing an adversary that there is no route to victory, whether through a surprise attack or through gradual escalation. That coherence limits an aggressor’s room for manoeuvre.

Technological Investment

To ensure that its adversaries have no doubt about the credibility of its deterrent, France continues to strengthen its capabilities. As rival powers modernise their defences and multiply demonstrations of force, the penetration capability of France’s nuclear forces remains essential to the protection of its vital interests.

The renewal of France’s nuclear arsenal through to 2035 is underpinned by the 2024-2030 Defence Spending Law (LPM) and reinforced by its recent update. At sea, the Strategic Oceanic Force (FOST) is preparing for the arrival of the third-generation nuclear ballistic missile submarines, whose acoustic stealth continues to push the boundaries of what is technologically possible. At the same time, the M51 submarine-launched ballistic missile is continuing its incremental evolution with the M51.4, ensuring its ability to penetrate even the most sophisticated missile-defence systems. In the air, the Strategic Air Forces (FAS) rely on the ASMPA-R weapon system while preparing to field the future ASN4G hypersonic missile. The complementarity of these two components means that any adversary seeking to make its defences impenetrable would have to deploy large numbers of interception systems based on very different technologies.

A Powerful, Sovereign, and Responsible Deterrent

Since the end of nuclear testing in 1996, the reliability of France’s nuclear weapons has depended on the expertise of the French Atomic Energy and Alternative Energies Commission (CEA). Through its Military Applications Directorate (DAM), France has developed an exceptionally sophisticated virtual simulation environment. The Simulation Programme is a cornerstone of that sovereignty by guaranteeing the performance and safety of new nuclear weapons without the need for any live testing.

It relies in particular on supercomputers and HPC (High-Performance Computing), as well as major experimental physics facilities that improve the accuracy of simulations, including the EPURE X-ray radiography facility at Valduc and the Laser Mégajoule (LMJ) at CESTA in Nouvelle-Aquitaine. The latter, for example, concentrates 176 laser beams onto a millimetre-scale target, recreating for a few billionths of a second the extreme pressure and temperature conditions of a thermonuclear explosion. This is how France can now develop new nuclear warheads, including the oceanic TNO (Tête nucléaire océanique) and airborne TNA (Tête nucléaire aérienne) versions, without ever conducting a nuclear test. Alongside this effort, DGA ensures full industrial control over the next generation of missiles, from the M51.4 to the ASN4G, as well as their carriers: the third-generation SSBN and the Rafale F5 combat aircraft. In this field, France remains fully independent: no critical component may depend on a foreign licence. Technical sovereignty is the foundation of strategic autonomy and ensures that France remains, whatever the circumstances, master of its own destiny.

Beyond Nuclear Forces: Strategic Support

To address the full spectrum of threats — and because nuclear deterrence cannot prevent every form of conflict below the nuclear threshold, including against another nuclear-armed state — French defence strategy relies on the mutual support between nuclear and conventional forces. Introduced by Emmanuel Macron in his 2020 speech at the École de Guerre, this concept dispels a long-standing misconception: the idea that nuclear weapons alone can provide an answer to every threat, at all times. It reflects the fact that nuclear and conventional forces are not two separate, isolated worlds, but rather two sides of the same strategic coin. Nuclear deterrence is the keystone protecting the Nation against existential aggression and strategic coercion. But for that keystone to remain credible, it must rest on strong conventional foundations: the Army, the Air and Space Force, and the French Navy, all capable of responding to threats that fall below the threshold of France’s vital interests. Without these robust conventional forces, the President of the Republic would be trapped in an “all-or-nothing” dilemma, forced to choose between capitulation and immediate nuclear escalation.

Strategic support enables France to respond to any act of aggression, demonstrate its resolve on the ground, compel an adversary to reveal its true intentions and, ultimately, force it to confront the risk of nuclear escalation should it persist. While forward deterrence gives concrete expression to the European dimension of France’s vital interests, “strategic support”, as the President of the Republic described it in his speech of 2 March 2026, reflects the determination to strengthen, together with our European partners, the conventional capabilities needed to counter any act of aggression or attempt at destabilisation on the European continent. France is thus committed to ensuring that no empire can turn a regional conflict into an existential threat to Europe. Conventional forces thus provide political leaders with the ability to act at the earliest possible stage alongside our partners while preserving their freedom of action, whereas nuclear deterrence guarantees the survival of the Nation.

The French Nuclear Naval Aviation Force (FANu)

Activated on the orders of the President of the Republic when required, the French Nuclear Naval Aviation Force (FANu) operates Rafale Marine aircraft capable of carrying the ASMPA-R nuclear missile from the aircraft carrier Charles de Gaulle. It can operate independently or alongside the Strategic Air Forces (FAS) as part of a coordinated strike.