resulted in more than 20,000 Arab casualties, with Israeli losses standing at fewer than 1,000 casualties. Alongside the combatant casualties were the deaths of 20 Israeli civilian killed in Arab forces air strikes on Jerusalem, 15 UN peacekeepers killed by Israeli strikes in the Sinai at the outset of the war, and 34 US personnel killed in the USS Liberty incident in which Israeli air forces struck a United States Navy technical research ship. At the time of the cessation of hostilities, Israel had seized Syria's Golan Heights, the Jordanian-annexed West Bank (including East Jerusalem), and Egypt's Sinai Peninsula as well as the Egyptian-occupied Gaza Strip. The displacement of civilian populations as a result of the Six-Day War would have long-term consequences, as around 280,000 to 325,000 Palestinians and 100,000 Syrians fled or were expelled from the West Bank and the Golan Heights, respectively. Nasser resigned in shame following Israel's victory, but was later reinstated following a series of protests across Egypt. In the aftermath of the conflict, Egypt closed the Suez Canal until 1975, providing a trigger for the 1970s energy crisis and 1973 oil crisis due to the impact on oil deliveries coming from the Middle East to Europe through the Suez Canal. Background After the 1956 Suez Crisis, Egypt agreed to the stationing of a United Nations Emergency Force (UNEF) in the Sinai to ensure all parties would comply with the 1949 Armistice Agreements. In the following years there were numerous minor border clashes between Israel and its Arab neighbours, particularly Syria. In early November 1966, Syria signed a mutual defence agreement with Egypt. Soon after this, in response to Palestine Liberation Organisation (PLO) guerilla activity, including a mine attack that left three dead, the Israeli Defence Force (IDF) attacked the village of as-Samu in the Jordanian-ruled West Bank. Jordanian units that engaged the Israelis were quickly beaten back. King Hussein of Jordan criticized Egyptian President Gamal Abdel Nasser for failing to come to Jordan's aid, and "hiding behind UNEF skirts". In May 1967, Nasser received false reports from the Soviet Union that Israel was massing on the Syrian border. Nasser began massing his troops in two defensive lines in the Sinai Peninsula on Israel's border (16 May), expelled the UNEF force from Gaza and Sinai (19 May) and took over UNEF positions at Sharm el-Sheikh, overlooking the Straits of Tiran. Israel repeated declarations it had made