Speaking at a podium high above the glistening black “Téméraire” ballistic missile submarine and following a solemn rendition of the French national anthem by the audience of military top brass, ministers and defense CEOs, Macron said: “A single one of our submarines, such as the one behind me, carries with it a strike force equivalent to the sum of all the bombs dropped on Europe during World War II.”

The French president outlined enhanced cooperation with European nations, naming Germany, Poland, Greece, the Netherlands, Belgium, Denmark and Sweden, which would include joint nuclear drills and ultimately, the potential temporary deployment of French nuclear-capable fighters in allied countries.

“I believe I can say that our partners are ready,” Macron stressed.

France and the U.K. are Europe’s only two nuclear powers. The French arsenal is both airborne and seaborne, with at least one submarine patrolling the seas at all times. Unlike the U.K., Paris is not part of NATO’s Nuclear Planning Group, although French presidents have always stressed that France’s vital national interests have a European dimension.

Monday’s speech is the result of months of work with European allies, an aide close to Macron said.

The French president first opened the door to a strategic nuclear dialogue with European allies in 2020 — but the proposal initially gained little traction. However, Russia’s full-scale invasion of Ukraine in 2022 underscored the danger posed by Moscow, while Donald Trump’s reelection as U.S. president raised questions about the reliability of U.S. security guarantees.