PARIS — France has officially introduced a modernized version of its submarine-launched ballistic missile, the M51.3, marking what officials describe as a “major milestone” in the nation’s ongoing nuclear deterrence modernization.
The Ministry of Armed Forces announced that the M51.3 features new nuclear warheads, improved range, and enhanced accuracy, alongside advanced capabilities to evade enemy missile defenses. The missile will be deployed aboard France’s four Le Triomphant-class nuclear-powered ballistic missile submarines.
“The M51.3 ensures the continued credibility of the ocean-based component in the face of evolving enemy missile defenses,” the ministry said in a statement.
Armed Forces Minister Catherine Vautrin signed the operational commissioning of the M51.3 on Friday. She described the development as central to the 2024–2030 Military Programming Law, emphasizing France’s commitment to strengthening deterrence and maintaining national sovereignty.
“This achievement embodies a major ambition — to accelerate the modernization of our capabilities and ensure the long-term credibility of our deterrence,” Vautrin stated on social media.
The new missile comes amid what the Stockholm International Peace Research Institute (SIPRI) recently called a dangerous global arms race. Nearly all nuclear powers, including Russia and the United States, are upgrading their arsenals to counter evolving missile defense systems.
France’s modernization efforts are also seen as part of its strategy to preserve “strategic autonomy” within NATO. Unlike other alliance members, France maintains full independence over its nuclear command and decision-making. However, in July, France and the U.K. agreed to explore coordination between their deterrent forces.
Developed under the supervision of the Directorate General for Armament (DGA), the M51.3’s TNO-2 nuclear warhead was designed by France’s Commissariat for Atomic Energy, with missile design and propulsion led by ArianeGroup.
The M51.3 is believed to have an intercontinental range exceeding 9,500 kilometers — an improvement over its predecessor’s 9,000 kilometers — and carries four to six independently targetable warheads, each estimated at 100 kilotons, according to the Bulletin of the Atomic Scientists.
Weighing over 50 metric tons and stretching 12 meters long, the three-stage solid-propellant missile reaches altitudes above 2,000 kilometers before reentry at speeds up to Mach 20.
France began developing the M51.3 in 2014, with its first test flight conducted from the Biscarrosse site in 2023. The missile succeeds the M51.1 and M51.2 versions that entered service between 2010 and 2016.
Beyond the M51.3, France is advancing its next-generation deterrence systems, including the ASN4G hypersonic air-launched missile and the Future Combat Air System (FCAS). These initiatives reflect the country’s long-term vision to sustain a credible nuclear deterrent well into the 2080s.