France test fired an upgraded M51 strategic ballistic missile from a submarine for the first time Tuesday, demonstrating a capability that President Emmanuel Macron described as vital to the country’s strategic credibility. Macron said allies and competitors would closely monitor the event.

The nuclear powered ballistic missile submarine Le Vigilant launched the M51.3 during an acceptance test conducted after the vessel’s overhaul, according to a statement from the Ministry of the Armed Forces. The missile did not carry a nuclear warhead.

The launch occurred off Finistère in western France. The missile later splashed down in the North Atlantic several hundred kilometers from any coastline, the ministry said.

Macron observed the launch from a French Navy vessel and addressed troops aboard the ship. “This is a very important moment for our strategic credibility,” he said.

The test was part of France’s broader effort to modernize its nuclear deterrence apparatus. That work includes upgraded M51 missiles, construction of new ballistic missile submarines and a future Rafale fighter jet upgrade involving a hypersonic nuclear cruise missile.

France is also working with several European allies on a proposal Macron has called “forward deterrence.” The concept could extend the reach of French nuclear deterrence to those allies, although the details remain vague.

Every major overhaul of a French nuclear powered ballistic missile submarine is followed by an acceptance test firing of the M51, the ministry told Defense News in an emailed response. Tuesday’s launch followed that established testing process.

ArianeGroup manufactures the M51. The company and France’s Directorate General for Armament completed the first flight test of the modernized missile from a launch site in Biscarrosse in southwest France in 2023.

The upgraded missile entered operational service in October last year. Tuesday’s event marked its first firing from a submarine after the earlier test from the land based Biscarrosse site.

The M51.3 is estimated to have a range exceeding 9,500 kilometers, compared with more than 9,000 kilometers for the previous version, according to the Bulletin of the Atomic Scientists. Its official range has not been disclosed.

ArianeGroup says the M51 reaches an altitude of more than 2,000 kilometers. It then reenters the atmosphere at a speed of Mach 20.

According to the Bulletin, the missile carries four to six multiple independently targetable reentry vehicles, known as MIRVs. The ministry said the M51.3 provides improved performance in range, accuracy and penetration capability.

The missile is equipped with the new TNO-2 oceanic nuclear warhead, although the missile fired Tuesday carried no nuclear warhead. The solid propellant, three stage missile weighs more than 50 metric tons.

France operates four ballistic missile submarines, and each can carry 16 M51 missiles. That force represents the ocean based component of the country’s nuclear deterrence.

“The M51.3 ensures the long-term credibility of the ocean-based component in the face of evolving adversary missile defenses,” the ministry said. “It reflects the commitment of the President of the Republic to maintaining operational credibility of the nuclear forces over the long term, at the level required by the international environment.”

The first M51 was fired from Biscarrosse in 2006. The first submarine launch followed in January 2010 from the ballistic missile submarine Le Terrible.

Tuesday’s firing was the seventh launch of an M51 variant from a French submarine and the missile’s 13th launch overall. The ministry said all of those launches were conducted without a nuclear warhead.

The M51.3 test therefore combined a routine acceptance requirement following Le Vigilant’s overhaul with the first submarine demonstration of the newest missile variant. For France, the launch placed its continuing nuclear modernization effort on public display before allies and competitors alike.