France fires its newest nuclear missile from a submarine

France test-fired its newest submarine-launched nuclear missile, the M51.3, from a ballistic missile submarine for the first time on Oct. 6, with President Emmanuel Macron watching from a French Navy frigate off the coast of Brittany.

The missile was launched from the submarine Le Vigilant off Finistère and came down in the North Atlantic several hundred kilometers from any coastline, the French Ministry of the Armed Forces said. It carried no nuclear warhead or other payload.

The launch had a practical purpose. Le Vigilant recently completed a long maintenance and modernization overhaul, and the test certified that the submarine can once again carry and fire the M51, the ministry said. French ballistic missile submarines go through a similar firing after each major refit; Le Terrible did so in April 2023.

Macron watched from the multi-mission frigate Auvergne and posted about the test on X.

“Very few nations possess such know-how,” Macron wrote, crediting France’s defense procurement agency DGA, the Atomic Energy Commission (CEA), ArianeGroup, Naval Group and the French Navy.

“This technical success is a new demonstration of the credibility of our deterrence, whose long-term future is assured,” Macron wrote. “To be free, one must be feared. And to be feared, one must be powerful.”

The M51.3 is the third version of the M51, a three-stage, solid-fuel ballistic missile built by ArianeGroup. The M51 family weighs more than 50 tonnes (55 tons) and is about 12 meters (39 feet) long. France does not disclose its range, but public estimates for the M51 family generally put it at around 9,000 km (5,600 miles) or more, and French officials have said the new version flies farther.

Work on the M51.3 began in 2014. The new version carries the TNO-2 nuclear warhead, developed by the CEA, and offers improved accuracy and a better ability to get through enemy missile defenses, according to the ministry. The missile’s first flight test took place in November 2023, when the DGA fired an unarmed M51.3 from its land-based Biscarrosse test site in southwestern France. The M51.3 entered operational service in October 2025.

France’s sea-based deterrent rests on four Le Triomphant-class ballistic missile submarines, Le Triomphant, Le Téméraire, Le Vigilant and Le Terrible, each with 16 missile tubes. At least one is at sea at all times. The M51.3 is gradually replacing the earlier M51.1 and M51.2 versions across the fleet, and ArianeGroup is already under contract for a fourth version, the M51.4.

In his post, Macron said he had launched a renewal of France’s nuclear forces in 2017 and that the armed forces’ budget will have doubled over ten years. He said France’s next-generation ballistic missile submarines are under construction and that a program for hypersonic, maneuvering strategic missiles for the airborne leg of the deterrent was launched this year.

“Our nuclear deterrence protects us and will continue to protect us,” Macron wrote.

The test follows Macron’s announcement in March that France would increase the size of its nuclear arsenal for the first time in decades. France is the only European Union member with nuclear weapons and maintains a stockpile of about 290 warheads for its submarine- and air-launched forces.