Following the allied invasion of Syria on 8 June 1941, No. 11 Commando was sent to successfully lead the crossing of the Litani River in Lebanon, fighting against troops of the French Vichy régime, during which Keyes played a leading part. In this operation, Keyes earned the Military Cross. Following the action, 11 Commando returned to Cyprus, then to Egypt in August 1941, where the unit was left in limbo. Keyes, who had assumed command of the unit after his commanding officer, Colonel Richard Pedder, was killed during the Litani River offensive, was authorized to retain 110 volunteers as a troop in the Middle East Commando.