The New French Forward Nuclear Deterrence, the Île Longue Roadmap

Before Mr. Macron spoke on March 2 at the naval base of l’Île Longue, there was room for doubt: wouldn’t this mandatory, once-a-term exercise-the major presidential address on nuclear deterrence-simply produce a repetition from successive presidents about the concept of "vital interests" (such "vital interests" can justify the recourse to nuclear weapons) that might entail a European dimension? Speeches that usually came up against the polite indifference of largely uninterested European partners?

With two weeks’ hindsight, one can observe that this doubt was actually unfounded. The Île Longue speech marks, if not a complete break, at least a genuine evolution, for threefold reasons: the scene has changed, the performance has gained in precision, and the European audience has, on the whole, this time responded favorably.

New Context, New Perception

The scene, that is to say the strategic context, has little in common with the one that prevailed during the latest speech in 2020. The author will not here paraphrase the indisputable diagnosis made by Emmanuel Macron regarding the worsening of the threat, its diversification, the interconnection between adversaries, the increased risks of crossing the nuclear threshold and of conflict below the nuclear threshold. For all allies, the danger obviously stems from Russia's lasting resurgence of aggressiveness at the very moment when the American guarantee appears less reliable. To the French, the realization also comes from the fact that nuclear deterrence does not completely shield us from any major attack: the Ukrainian breakthrough in Kursk has shown the limits of the status of a nuclear-weapon state in deterring a resolute aggressor. In this 2026 version of the deterrence speech, under the guise of an aggiornamento of the conventional forces' "backing" of the nuclear weapon,lies an admission of our weaknesses in the modern components of conventional warfare- also highlighted by the war in Ukraine: early warning, air defense, and deep strikes.

This brings us to the performance itself, the content of the presidential address. It includes a reminder of the strengthening of our cooperation with the United Kingdom and proposals previously made regarding dialogue with certain partners on nuclear matters or participation in certain exercises. Aside from the acknowledgment of the change in the conventional equation already noted, new elements must be added, such as the possibility of temporary deployments of French "strategic force elements" (with or without nuclear weapons on board?) on the soil of European partners, and the raising of the ceiling of our nuclear arsenal. On this last point, the British had preceded France. This decision was essential to lend credibility to our adaptation to the new threat level and our willingness to develop with certain partners this ‘forward deterrence’ that would result from all the measures mentioned above.

But, overall, the most significant change came from the reception given to the French proposals. In the speech itself, the president mentions six countries, in addition to Germany and the United Kingdom, that have already agreed to the proposed dialogue: Belgium, the Netherlands, Poland, Greece, Sweden, and Denmark. Others have since expressed their interest. A Franco-German statement, released immediately after the presidential speech, announces the establishment of a "high-level nuclear group" between the two countries. Let us commend the diplomatic engineering that secured the support of these partners even before the public announcement of the French proposals. Admittedly,Macron’s speech spares no effort in assuring that his proposals are meant to complement rather than compete with the U.S. extended deterrence within the NATO framework. However, it is worth noting that the president emphasizes that not only would the decision to press the nuclear button, should the need arise, remain a French one-which goes without saying-but that the same applies to the planning of our nuclear capabilities and the definition of vital interests. He even goes so far as to say that our offers do not strictly speaking constitute a 'security guarantee'. It is against this backdrop that we must assess the positive reaction of our European partners.

Will this reaction last? What will happen now? An initial part of the answer will come from the United States; indications suggest that Washington was not hostile to the developments envisioned by Paris-perhaps out of mere indifference. However, one cannot rule out that, at a given moment, an imperialist reflex might put a stop to French inclinations toward 'forward deterrence' (or at least to their endorsement by other allies). A second factor will result from the development of dialogue with our partners, both in the nuclear and conventional spheres. From this perspective, Macron’s speech constitutes less a proclamation of a new doctrine than the outline of a roadmap; the path ahead can only be navigated in cooperation with a European coalition of the willing, and many doctrinal and operational questions deliberately remain open.

Implicit Proposals

In his analysis published by the International Institute for Strategic Studies, Bruno Tertrais, a leading expert in military nuclear strategy, brilliantly catalogs the omissions of the Île Longue speech. Many observers were quick to point out one of the major unspoken elements of the forward deterrence proposal: explicitly, it aims to offer a complement to American extended deterrence, intended to "complicate the calculations of [the] adversaries" (to quote Mr. Macron); but implicitly, it is also about being able to prepare a fallback option-at least for certain European countries-in the event that the American nuclear umbrella were to close. It is significant in this regard that three of the countries that have accepted the French proposal for a nuclear dialogue (Germany, Belgium, the Netherlands) are countries where American nuclear weapons are stationed.

Another Unspoken Aspect of the Roadmap

Finally, behind this affair lies another unspoken factor, at the forefront of most minds in other European capitals: where will France stand on such issues after the 2027 presidential elections? One could say that the reaction of virtually the entire French political class has been rather positive and therefore encouraging. Leaders of most parties seem to have grasped a key point: while the Île Longue proposals mark various steps forward-or at least a direction-the very nature of the speech as a roadmap means these proposals do not tie the hands of future leaders.

Another way to view this aspect of the situation can be found in the reactions of a group of "transatlantic" experts gathered by the Carnegie Europe Foundation under the direction of Rym Momtaz: for some, the ideas in the Île Longue speech go too far, for others, they do not go far enough. We may hence conclude that the President of the Republic has struck a good balance.
 

Copyright Yoan VALAT / POOL / AFP
Emmanuel Macron in front of the nuclear submarine "Le Téméraire" at the Île Longue naval base, March 2, 2026.