France has officially unveiled the M51.3, the modernised version of its submarine-launched strategic ballistic missile M51, in what is described as a “major milestone” in the modernisation of its ocean-based nuclear deterrence strategy. This latest version has new nuclear warheads, as well as improved range, accuracy and the ability to penetrate enemy defences, the French Armed Forces Ministry said on Tuesday.
Second Strike Assurance Against Emerging Threats
The M51.3 missile will be deployed on the country’s four Le Triomphant nuclear-powered ballistic missile submarines. The missile “enables the ocean-based component to maintain reliability in the face of adversary’s evolving missile defence systems,” the ministry said. At a time when potential rivals such as Russia are modernising their ballistic missile defence capabilities, the M51.3 upgrade is vital to France’s continued nuclear deterrence posture by reinforcing its ability to provide a credible second-strike capability.
Signing the document on the operational commissioning of the missile, Minister of the Armed Forces Catherine Vautrin noted that this achievement represents one of the key objectives of the 2024-2030 Military Programming Act, namely to ensure the long-term reliability of deterrence as a pillar of security.
Technical Capacity and Strategic Autonomy
The M51.3 programme was overseen by the Directorate General of Armaments (DGA), while the new TNO-2 warhead was developed by the Atomic Energy Commissariat and ArianeGroup was responsible for the design and propulsion of the missile.
The M51 missile has an intercontinental range and carries multiple nuclear warheads. According to ArianeGroup data, each submarine is equipped with 16 missiles weighing more than 50 tonnes. According to the Bulletin of the Atomic Scientists, the range of the M51.3 is estimated to be over 9, 500 kilometres, up from the previous iteration of over 9,000 kilometres. The missile is said to carry four to six independently targetable re-entry vehicles (MIRVs), each with a power of 100 kilotons.
Comprehensive Modernisation in Air and Sea
Work on the M51.3 began in 2014 and the first test flight was successfully completed in November 2023. As part of its nuclear modernisation, France is working to renew not only its missiles, but also its Le Triomphant class submarines from the 2030s (SNLE 3G programme).
In addition to the sea-based component, France is also working on the air-launched ASN4G hypersonic missile, which will replace the ASMPA nuclear cruise missile carried by the Rafale fighter jet. All these projects demonstrate France’s determination to maintain what it calls its strategic autonomy within NATO.
