How France’s new nuclear doctrine strengthens NATO

In his March 2 speech delivered from the Île Longue naval base, President Emmanuel Macron announced major changes to France’s nuclear doctrine. Macron’s speech aimed to adapt to new global geostrategic challenges, chief among them being the return of high-intensity conflict on European soil.

President Macron announced that France will increase its nuclear arsenal, marking the end of its near-continuous decline since the end of the Cold War. Most significantly, Macron introduced a new strategic concept of forward deterrence (dissuasion avancée), which paves the way for active participation by selected European allies in French nuclear operations.

These changes to France’s nuclear doctrine mark a revolution. But not a revolution that questions the transatlantic security. One that reinforces it.

This initiative primarily aims to demonstrate European cohesion in the realm of common security, including the nuclear domain. It comes as its US partner now focuses its attention on other operational theaters, particularly in the Indo-Pacific. But France’s forward deterrence is not intended to replace the US extended deterrence. Rather, it seeks to complement it. While some may point to potential frictions between the two approaches— including over the allocation of resources—their methods, scopes, and objectives differ. These differences create space so that the French forward deterrence and the US extended deterrence can coexist within the North Atlantic alliance and even strengthen it.

Political and operational opening. Since their inception in the 1960s, France’s strategic forces have trained to conduct nuclear operations in complete autonomy, ensuring that the supreme political decision-maker can, under any circumstances, order a nuclear strike against any aggressor threatening the country’s vital interests. This commitment to total autonomy—particularly vis-à-vis the United States—explains France’s decision not to participate in NATO’s Nuclear Planning Group.

The opening of French nuclear operations to allied participation is not an admission of weakness but rather a powerful signal of European cohesion sent to the continent’s strategic competitor (one adversary or a coalition of adversaries). Such arrangements already exist within NATO, with at least 13 European states actively involved in the Alliance’s nuclear operations—whether through the deployment of US B-61 nuclear bombs on dual-capable aircraft or through NATO’s conventional support to nuclear operations. While this frees up US capabilities for other missions, it in no way diminishes Washington’s ability to conduct nuclear operations autonomously and therefore the credibility of its nuclear deterrence. Above all, this is a political signal. The same will apply to France.

The March 2 speech builds on last July’s French-UK Northwood Declaration, which for the first time announced coordination between the two countries in nuclear operations. However, where the Northwood Declaration remained vague by not specifying how this coordination would materialize, the Île Longue speech outlined an incremental plan to gradually integrate eight allied states (since joined by Norway as the ninth member, and Finland has expressed interest in joining) into French nuclear operations. Through this coordination, France seeks to familiarize these countries’ forces with the specifics of French deterrence and to train French strategic forces in nuclear operations in a coalition.

Gradual approach. Of the nine partner states involved in the forward deterrence initiative, four are nations operating NATO’s dual-capable aircraft (Belgium, Germany, Greece, and the Netherlands). They will soon be joined by the United Kingdom, which recently announced its intention to acquire F-35As for this mission and already possessed an air-delivered nuclear capability in the past. The air forces of these countries, therefore, already have solid experience in nuclear weapons deployment. The other four nations (Denmark, Norway, Poland, and Sweden) contribute to NATO’s conventional support to nuclear operations, which they regularly train for, particularly during the annual Steadfast Noon nuclear exercise.

The first step in Macron’s gradual approach is logically the participation of these countries’ armed forces in certain French nuclear exercises. Their participation may be modeled after the quarterly Poker operation conducted by the French Strategic Air Forces, which simulates a full nuclear strike against a fictional adversary equipped with the most advanced anti-access/area denial capabilities, including very long-range air and missile defenses. While the nine partners are already familiar with NATO nuclear operations, these differ significantly from France’s, especially because of differences in delivery systems: NATO’s dual-capable aircraft (F-16, Tornado IDS, and F-35A) use gravity bombs requiring release close to the target, whereas France’s Rafale B aircraft deploy the supersonic ASMPA-R air-launched cruise missile with a range of several hundred kilometers. This allows for stand-off strikes, which are attacks that can target from a distance by launching long-range missiles well beyond the reach of most adversary air defense systems. The modes of action and required means are therefore markedly different: The French approach resembles a hit-and-run operation, while NATO’s requires extensive battlefield shaping before the strike.

The second step in cooperation will involve strategic signaling. It aims to demonstrate France’s determination to protect its interests, “fully factoring in the interests of our allies” into its calculus—including, if necessary, by leveraging its nuclear forces. In peacetime, this could involve temporary deployments of aircraft or even nuclear-powered ballistic missile submarines to allied military bases. The strategic air forces are already accustomed to operating on allied territory, such as during reassurance missions on NATO’s eastern flank or Agile Combat Employment exercises. However, they have so far done so as conventional forces, due to their dual-capable nature, much like NATO’s dual-capable aircraft squadrons. The March 2 speech changes this: From now on, any deployment of strategic air forces to one of the nine partner countries will have an implicit or explicit nuclear dimension. Carrying actual nuclear weapons during reassurance missions is very unlikely because France prohibits flying live nuclear weapons during peacetime. But the ASMPA-R missile mockups used in strategic exercises could visually and symbolically underscore the nuclear nature of the maneuver. Beyond signaling France’s support for its allies, these peacetime activities will also allow allied personnel to train in the maintenance of French aircraft and their nuclear armament, enabling them to sustain operations in a crisis.

The third and final step of Macron’s plan is the deployment of strategic forces abroad during a crisis, which gives forward deterrence its full meaning. The dispersion of aircraft contributing to the nuclear mission across foreign bases and airfields serves to increase force survivability in the event of a surprise strike by an adversary and to send a major strategic signal, marking a new threshold in conflict escalation. Until now, such dispersion was only envisaged on French territory. It is regularly practiced by the strategic air forces during POKER operations and by conventional forces during major exercises involving fighter jets and air tankers. Opening the territories of nine European partners to French nuclear operations now nearly quadruples the area in which the strategic air forces can operate, significantly complicating adversary planning for a disarming strike. It would also increase the political cost of such an attack, as it would require massive strikes against 10 countries instead of one, thereby diluting the risks of coercion by an adversary.

Complementarity with US extended deterrence. The March 2 speech was prepared in full transparency with the US partner, who was informed of France’s intentions ahead of the announcement. NATO was also informed, with Macron emphasizing that “this effort will come as an addition to NATO’s nuclear mission,” adding that “the forward deterrence we are proposing is a distinct effort which has its own value and is perfectly complementary to NATO’s at both strategic and technical level.”

France’s philosophy on nuclear weapons use differs significantly from NATO’s. Doctrinally, France rejects the concept of graduated or flexible nuclear response: Crossing the nuclear threshold is only conceivable in the most extreme phase of a conflict, if there is an attack on the country’s vital interests, which includes their European dimension. Before massive retaliation, France may conduct only a single nuclear warning in the form of a limited nuclear strike against one or possibly several targets. This warning seeks to signal to the adversary the change in the nature of the conflict and to restore deterrence, while demonstrating France’s determination to use nuclear weapons to defend its vital interests. This limited strike, which is strategic in nature, does not intend to gain a military advantage but is political in purpose. It would be accompanied by political and diplomatic messages to the adversary, indicating France’s intentions. The Strategic Air Forces are often presented as the preferred instrument—compared to a submarine launch—for this action because the multiple escalation steps can be observed by intelligence means, allowing the adversary to see that it is approaching a point of no return. The ability to recall the raid even if already en route is also a significant advantage to maintain strategic stability, as it allows potential final negotiations before the engagement order is transmitted.

In contrast, NATO’s nuclear capabilities—particularly US non-strategic nuclear forces—enable a graduated response to any adversary aggression, conventional or nuclear, at any scale. This could include, for example, a symmetrical response to the use of tactical nuclear weapons on the battlefield by the adversary. As a result, NATO nuclear forces would likely engage before France’s in a crisis involving one of the nine countries involved in France’s initiative, though a parallel escalation of both postures is possible, if only for strategic signaling purposes toward the adversary.

The nature of the targets would also likely differ due to the delivery systems used. Therefore, French nuclear forces—potentially supported by allied aircraft—provide access to a wide range of targets located deep inside adversary territory but without requiring an important operational footprint.

Even in the event of parallel engagement of French and NATO nuclear postures, the deployment of certain conventional assets would benefit both, particularly in terms of suppression of enemy air defenses along the front lines. Moreover, a French nuclear strike package is relatively small: around 20 combat aircraft, accompanied by a few air tankers and an airborne early-warning and control aircraft, which is a scalable configuration depending on the mission. Likely, its execution would primarily involve French aircraft, with the participation of allies probably being limited to a few aircraft with specific air-defense suppression or stealth capabilities to enhance the penetration capabilities of the French strike.

The ability to use allied air bases from the northern to southern Eastern Flank of NATO is likely the main operational asset of France’s forward deterrence, allowing for diversified axes of penetration for the strike, as well as potentially shorter flight times and access to new sets of targets, like in the Arctic. This complicates adversary defense planning by forcing it to disperse its most advanced air and missile defense systems both along the front lines and deep inside its territory. (Russia recently conducted “surprise” strategic exercises that, according to Russian Deputy Foreign Minister Alexander Grushko, were programmed to address France’s new doctrine.) In return, this dilution of enemy defenses would also benefit NATO’s nuclear operations.

Need for a new nuclear coordination structure. While the French and US deterrence approaches are complementary and driven by different logics, they will require coordination mechanisms to prevent any dispute over the allocation of resources for their missions. Coordination will also be needed to maintain coherence and control over escalation against a common adversary. If ambiguity is inherent to nuclear deterrence, it must not create confusion, because it would be detrimental to the credibility of the Alliance’s resolve. Given France’s jealously guarded autonomy in nuclear decision-making—particularly vis-à-vis the United States—Paris likely will remain outside NATO’s Nuclear Planning Group, which requires more coordination effort.

Exchanges already exist among the Alliance’s three nuclear powers (France, the United Kingdom, and the United States) under the so-called “P3” format. Although little information is available about the topics discussed in these exchanges, they appear to focus primarily on nuclear policy. It could be beneficial to expand them to operational themes, following the model of the French-UK Northwood Declaration, which opens the door to deepened cooperation while preserving each party’s autonomy.

Such coordination is vital to ensure a united front in a conflict, thereby limiting an adversary’s ability to exploit potential divisions among allies. It also provides non-nuclear allies with a clear and reassuring understanding of the shared control over escalation between the three nuclear powers.

If France’s nuclear deterrence was already recognized as contributing significantly to the Alliance’s overall security, the forward deterrence concept now reinforces its role by offering a complementary approach to US extended deterrence. The diversity of modes of action and objectives between the two models will help avoid competition for resources in a crisis while further complicating potential adversaries’ calculations. However, coordination between the two approaches will be necessary, potentially through a new structure, which is independent of NATO’s Nuclear Planning Group and also includes the United Kingdom. This would maintain coherence across the Alliance’s entire nuclear architecture while preserving the autonomy of each party.

The participation of nine European states already deeply involved in NATO’s nuclear operations lends operational and political credibility to the French initiative, while discussions are underway to include additional states, like Finland and the Czech Republic. Paris’s security offer could also prove invaluable in the event of a major US commitment in the Indo-Pacific, deterring Russia from launching an opportunistic attack against one or more NATO’s Eastern Flank states, thereby strengthening Europe’s strategic stability.