In the early 1950s, Egypt violated the terms of the Egyptian-Israeli armistice agreement and blocked Israeli ships from passing through the Suez Canal, a major international waterway. It also began to block traffic through the Straits of Tiran, a narrow passage of water linking the Israeli port of Eilat to the Red Sea. This action effectively cut off the port of Eilat -- Israel's sole outlet to the Red Sea and Indian Ocean. Closure of the Suez Canal and the Tiran Straits damaged Israel's trade with Asia, for it meant that foreign ships carrying goods bound for Israel and Israeli ships carrying goods bound for the Far East had to travel a long and costly circuitous route to the Atlantic and Israel's Mediterranean ports.
At the same time, Palestinian Arab fedayeen launched cross-border infiltrations and attacks on Israeli civilian centers and military outposts from Egypt, Jordan and Syria. Arab infiltration and Israeli retaliation became a regular pattern of Arab-Israeli relations. Israel hoped that its harsh reprisals would compel Arab governments to restrain infiltrators into Israel. In 1955 alone, 260 Israeli citizens were killed or wounded by fedayeen.
In July 1956, Egyptian President Gamal Abdel Nasser nationalized the Suez Canal, threatening British and French interests in oil supplies and western trade. Their interests converging, Israel, Britain and France planned an attack on Egypt, with the former seeking free navigation through international waters and an end to terrorist attacks and the latter two hoping to seize control of the Suez Canal.
On October 29, 1956, Israel began its assault on Egyptian military positions, capturing the whole of the Gaza Strip and the Sinai Peninsula. On October 31, France and Britain joined the fray and hostilities ended on November 5. The U.S. was caught completely by surprise and voiced strong opposition to the joint attack. The U.S. pressured Israel to withdraw from Egyptian territory. United Nations forces were stationed along the Egyptian-Israeli border to prevent an Egyptian blockade and deter cross-border infiltrations. Israel declared that if Egyptian forces would again blockade the entrance to the Gulf of Aqaba, it would consider this a casus belli.