Operation Menace was an Allied plan to either persuade Dakar to join the Allied cause, or capture it by force. De Gaulle believed this was possible. Among the units taking part was the newly formed FAFL "Groupe de Combat Mixte" (GMC) 1, code-named "Jam", consisting of four squadrons composed of Bristol Blenheim bombers and Westland Lysander liaison/observation aircraft. The Battle of Dakar was a failure, however. The port remained in Vichy hands, the FAFL envoys were arrested and imprisoned at Dakar by the Vichy authorities, and de Gaulle's standing was damaged.