France has conducted the first submarine launch of its upgraded M51 strategic ballistic missile, test-firing the latest version from a nuclear-powered ballistic-missile submarine on Tuesday. President Emmanuel Macron described the demonstration as an important milestone for France’s strategic credibility, adding that both the country’s allies and potential adversaries would be closely watching the development.
The French Navy’s nuclear-powered ballistic-missile submarine Le Vigilant launched an M51.3 missile during an acceptance test following the vessel’s major overhaul, according to France’s Ministry of the Armed Forces. The missile was not fitted with a nuclear warhead. It was launched from waters near Finistère in western France and landed in the North Atlantic, several hundred kilometers away from any coastline.
The M51 modernization program, developed by ArianeGroup, forms part of France’s broader effort to maintain and upgrade its nuclear deterrent. That effort also includes the development of a new generation of ballistic-missile submarines and a future modernization of the Rafale fighter aircraft, which is expected to carry a hypersonic nuclear-capable cruise missile.
“This is a very important moment for our strategic credibility,” Macron told French military personnel aboard a French Navy vessel from which he watched the launch. He said recent developments and the latest test would receive significant attention from both France’s allies and competitors, describing the launch as another step in the strategic direction the country has chosen.
The modernization effort comes as France is also discussing closer cooperation with several European allies on what Macron has described as “forward deterrence.” The concept could eventually involve extending aspects of French nuclear deterrence to European partners, although the precise arrangements remain undefined.
France’s Ministry of the Armed Forces told Defense News that an acceptance firing of the M51 is carried out following every major overhaul of one of the country’s nuclear-powered ballistic-missile submarines.
ArianeGroup and France’s Directorate General for Armament conducted the first flight test of the upgraded M51.3 in 2023 from the Biscarrosse missile test facility in southwestern France. The modernized missile subsequently entered operational service in October 2025.
According to estimates from the Bulletin of the Atomic Scientists, the M51.3 has a range exceeding 9,500 kilometers, compared with more than 9,000 kilometers for the preceding version. The missile is also reported to carry between four and six independently targetable reentry vehicles, or MIRVs.
France does not publicly disclose the missile’s official range. ArianeGroup, however, states that the M51 can reach an altitude above 2,000 kilometers before descending through the atmosphere at speeds of approximately Mach 20.
The upgraded missile incorporates the new TNO-2 oceanic nuclear warhead and is intended to provide improved range, accuracy, and penetration performance, according to the French defense ministry. The three-stage missile uses solid propellant and weighs more than 50 metric tons. Each of France’s four ballistic-missile submarines is capable of carrying up to 16 M51 missiles.
According to the ministry, the M51.3 is designed to preserve the long-term credibility of France’s sea-based nuclear deterrent as opposing missile-defense capabilities evolve. The modernization is also intended to maintain the operational effectiveness of France’s nuclear forces over the long term in response to changing international security conditions.
The original M51 was first launched from the Biscarrosse test site in 2006. Its first submarine launch took place in January 2010 from the Le Terrible ballistic-missile submarine.
The latest test represents the seventh launch of an M51 variant from a French submarine and the 13th launch of the M51 missile overall. According to the French defense ministry, every one of these tests has been conducted without a nuclear warhead.
