Causes of the war :
Vital British interest : The Suez Canal provided Britain with a shorter sea route to its empire and, as the 20th century dawned and oil grew in importance, it provided a short sea route to the oilfields of the Persian Gulf. Britain was, therefore, committed to protect the canal.
The crisis builds : The Suez Crisis of 1956 has its roots in the post-war upsurge of nationalism in Egypt. In 1951, Nahas Pasha, leader of the recently-elected nationalist Wafd party revoked the Anglo-Egyptian Treaty of 1936. British threats to occupy Cairo prompted King Farouk of Egypt to dismiss Nahas Pasha, but in July 1952 Farouk was overthrown in a military coup and General Mohammed Neguib seized power in 1954, Colonel Gamel Abdul Nasser replaced General Neguib. He had three goals: to make Egypt independent by ending British occupation; to build up Egyptian forces for a successful attack on Israel; to improve Egypt’s economy by constructing a high dam at Aswan to irrigate the Nile valley.
Appeasement fears : In February 1955, Anglo-Egyptian affairs were strained once more by Eden’s decision to deprive Nasser of promised British arms. In April, Eden succeeded Winston Churchill as the Prime Minister.
Treaties and collusion : The end of the Second World War in 1945 had brought a period of rapid change. The creation of the state of Israel in 1948 was followed by the first Arab-Israeli War, and a renewed upsurge of Arab nationalism made the Middle-east a volatile region. The United States had emerged from World War II as a global super power and, as a former colony itself it was committed to overseeing the decolonization of the globe.
Military action : On 29 October 1956, the Israeli attack was spearheaded by an airborne drop to seize control of the Mitla Pass. On 5 November, some three months and 10 days after Nasser had nationalized the canal, the Anglo-French assault on Suez was launched. It was preceded by an aerial bombardment, which grounded and destroyed the Egyptian Air Force. At midnight on 6 November, a cease-fire was called on the insistence of UN Secretary General Dag Hammarskjold. The AngloFrench forces had reached El Cap, just south of Port Said, but were not yet in control of the entire canal when they were stopped. Militarily, the operation was well on its way to being a great success.
Britain, France and Israel to withdraw their troops from Egypt. In Britain too there had been widespread outrage. A United Nations peacekeeping force was sent in to supervise the ceasefire and to restore order. The Suez Canal was cleared and reopened, but Britain in particular found its standing with the US weakened and its influence ‘east of Suez’ diminished by the adventure.