france M-20

M-20 (Jane's Strategic Weapon Systems)
Originated From:France
Possessed By:France
Basing:Submarine-launched
Length:10.70 m
Diameter:1.50 m
Launch Weight:20000 kg
Payload:Single warhead
Warhead:Nuclear 1.2 MT
Propulsion:Two-stage solid propellant
Range:2500 kt
Status:Obsolete
In Service:1977-1991

The M-20 was an intermediate-range, submarine-based, solid-propellant ballistic missile. It was the third member of France’s MSBS (Mer-Sol-Balistique-Stratégique) sea-launched nuclear deterrent force, replacing the earlier M-2 and the original M-1 design. The M-20s were originally deployed in sets of 16 missiles on nuclear submarines. 1

Under Charles de Gaulle, France pursued an alternate nuclear program to NATO, the goal of which was to function autonomously and provide France with the ability to escalate conflicts quickly. The M-20 was designed as the core of the sea-based French nuclear force. With a large 1.2 MT warhead, the M-20 was a strategic weapon meant for use against civilian population centers. Its low accuracy prevented it from being used against hardened missile targets. Thus, the M-20 was viewed as a second-strike weapon designed for retaliatory attacks.

Cutaway diagram of a M-20 SLBM in its launch tube.
Global Security (www.globalsecurity.org)

The main advantage of the M-20 was that its submarine had the ability to penetrate territorial waters and strike targets deep within the hostile country. Given the distance of France from the US, China, and Russia, this was the only option to allow for strikes against key population centers until the development of an intercontinental ballistic missile (ICBM). Due to the fact that it was based on a submarine, the M-20 could be hidden from a preemptive strike and reach most key targets, making it an ideal deterrent weapon.

The M-20 was 10.7 m long, 1.5 m in diameter, and weighed 20,000 kg. It used a two-stage solid propellant engine and had a range of 2,500 km (1,553 miles). Its inertial guidance system gave it an accuracy of 1,000 m CEP. The M-20 carried a single separating warhead with penetration aids to increase its ability to penetrate anti-missile defenses. It was equipped with a 1.2 MT yield TN-60 nuclear warhead. 2

The M-20 system entered service in France in 1977 and one hundred missiles were produced. In 1985, the new M-4 missile entered service, and in 1991 the M-20 ceased operational deployment. 3

Last Updated 9/17/2012

  1. Lennox, Duncan. “M-20.” Jane’s Strategic Weapon Systems (Obsolete Systems). October 13, 2011. (accessed September 12, 2012).
  2. Ibid.
  3. Ibid.
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