Egyptian army in the 1948 Arab–Israeli War, dissatisfied Egyptian officers created a secret organisation, the Free Officers. Led by Muhammad Naguib and Gamal Abdel Nasser, the Free Officers overthrew King Farouk in the Egyptian coup d'état of 1952. The Free Officers then concluded the Anglo–Egyptian Agreement of 1954, made during the month of October, with Great Britain. It stipulated a phased evacuation of British troops from the Suez base, agreed to withdrawal of all troops within 20 months (that is, June 1956); maintenance of the base was to be continued; and allowed Britain to hold the right to return for seven years. The last British combat unit left by 24 March 1956. Soon afterwards, the Suez Crisis arose, known in Egypt and the Arab World as the Tripartite Aggression. Just before the Suez Crisis, politics rather than military competence was the main criterion for promotion. The Egyptian commander, Field Marshal Abdel Hakim Amer, was a purely political appointee who owed his position to his close friendship with Nasser. A heavy drinker, he would prove himself grossly incompetent as a general during the Crisis. Rigid lines between officers and men in the Egyptian Army led to a mutual "mistrust and contempt" between officers and the men who served under them. Egyptian troops were excellent in defensive operations, but had little capacity for offensive operations, owing to the lack of "rapport and effective small-unit leadership". Tsouras writes that the mobilised strength of the army in October 1956 was 100,000, in 18 brigades (of which 10 were infantry, 2 armoured, 1 armoured training, and 1 medium machine-gun). The main manoeuvre formations were concentrated in the Sinai (30,000 in two divisions) or in the Canal Zone (one division). The field formations were preoccupied with changing over from British and American to Soviet military equipment. But after the Israeli attack started, "[t]he Egyptians in the Sinai never had a chance.' The Israelis seized the advantage, severed all the fragile seams in the organisation of the Egyptian forces, and destroyed their defences. Nasser ordered retreat from the Sinai which turned into a rout. By November 1957, the CIA wrote that the Egyptian ground forces were estimated to have a strength of 70,000 in combat units, and a total strength of 100,000. While there were three infantry divisions & one armoured division headquarters, they only performed administrative duties. The largest Egyptian combat units were the seven infantry