France Conducts First Sea Launch of M51.3 Nuclear-Capable Missile from Submarine Le Vigilant

Key facts

• On October 6, 2026, France test-fired its M51.3 nuclear-capable submarine-launched ballistic missile from the submarine Le Vigilant off the coast of Brittany, the variant's first launch from a submarine rather than a land site.
• The unarmed missile flew over the North Atlantic; the launch was an acceptance firing after Le Vigilant completed an overhaul, conducted with the DGA and CEA.
• The M51.3 entered operational service in October 2025 and equips the four Le Triomphant-class submarines based at Île Longue, each carrying 16 missiles.
• The solid-fuel M51.3 weighs over 50 tons, reaches beyond 1,240 miles, and reenters at about Mach 20 with multiple independently targeted warheads; independent estimates put its range above 5,900 miles.
• President Emmanuel Macron observed the launch from the frigate Auvergne and said it demonstrated the credibility of France's nuclear deterrent.
• France fields about 290 warheads, the world's fourth-largest arsenal, and is the European Union's only nuclear power, spending roughly €5.6 billion ($6.04 billion) a year on the force.
• ArianeGroup built the missile, and in August 2025 was awarded a contract to develop the next variant, the M51.4; a new class of ballistic-missile submarines is set to replace the Le Triomphant boats in the mid-2030s.