As a result of the 1956 Suez Crisis, Israel had possession of the Sinai Peninsula. In 1957, Israel was pressured by the United States to withdraw from the Sinai Peninsula, and a United Nations Emergency Force (UNEF) was stationed there to protect Israel’s right of passage through the Straits of Tiran (between Egypt and the Sinai Peninsula) and to keep Sinai from being remilitarized. As a result, the port of Eilat became Israel’s second busiest seaport and its main source of oil imported from Iran.
On the other side of the Straits of Tiran, Egyptian President Gamal Abdel Nasser had been humiliated by the 1956 defeat by the Israelis. In early May 1967, Moscow was circulating false reports that Israeli troops were massing on the Syrian border. Nasser feared that Israeli troops would also gather on the Egyptian border and felt compelled to uphold the mutual defense pact he had signed with Syria. On May 19, Nasser banned the 3,500 UNEF troops from Sinai so that he could mobilize Egyptian forces without interference. He began to close the Straits. Nasser’s Vice-President Abdel Hakim Amer announced, “It is high time to put a decisive end to Israel’s policy of bragging and arrogance” (Christian Science Monitor, May 20, 1967). View this video to learn more.
Two days later, on May 21, Egypt called up its full reserves and moved them into Sinai. Addressing air force officers in Sinai on May 22, Nasser stated,
We are ready for war…These waters are ours. War might be an opportunity for the Jews, for Israel, to test their strength against ours. The Israeli flag shall not go through the Gulf of Aqaba. Our sovereignty over the entrance to the Gulf cannot be disputed. If Israel wishes to threaten war, we tell her: “You are welcome.” (Boston Globe, May 23, 1967)
Prime Minister Levi Eshkol saw the move as an act of aggression; the UN and other nations tried unsuccessfully to diffuse the situation. On June 5, Israel pre-emptively struck against Egypt and the June 1967 Six Day War began.
The photo shows IDF tanks moving into the Negev on May 22, 1967.