The Sinai Campaign, 1956

In September 1955, in violation of international agreements and in what amounted to an act of war, Egypt sealed off access to the Israeli port of Eilat, effectively stopping Israel's sea trade with much of Africa and the Far East. Then, on July 26, 1956 Nasser announced Egypt’s nationalization of the Suez Canal, most of whose shares were held by Britain and France. With diplomacy failing to reverse Nassers’s decision, Britain and France embarked on preparations to regain control of the Canal, and on October 29, 1956 together with Israel, launched a military operation in the Sinai Peninsula. Four and a half months later, on March 16, 1957, Israel withdrew her troops from the Sinai and Gaza strip after receiving international reassurances that Israel's vital waterways would remain open. Three thousand three hundred United Nations troops replaced them. Despite Israel's withdrawal, the Egyptians refused to open the Suez canal to Israeli shipping.

Sachar, History of Israel, p. 456.