Israel preemptively attacked Egypt on June 5, 1967. After a month of increasing regional tensions escalated by Egypt (spurred on by the Soviets) and failed diplomatic efforts to calm the situation, Israel’s leaders believed they had no choice but to strike first. Within hours, Jordan and Syrian forces attacked Israelis forces.
In May 1967, events in the region led Israel to expect that an Arab attack was imminent. Egyptian President Gamal Abdel Nasser had ordered a withdrawal of the U.N. forces on the border and announced a blockade of Israeli goods through the Straits of Tiran. At the same time, Syria increased border clashes along the Golan Heights and mobilized its troops.
Israel held back on military action but international diplomatic efforts, led by U.S. President Lyndon B. Johnson, to stop the blockade failed. Egypt, Syria, Jordan and others began to mobilize their troops, and Arab leaders called for a war of total destruction against Israel. Israel feared a joint attack along three borders — with Egypt, Syria and Jordan. Arab mobilization compelled Israel to mobilize its own troops, 80 percent of which were reserve civilians. Israel launched a preemptive strike against Egypt on June 5. In rapid speed, the smaller but better trained and commanded Israel Defense Forces captured the Sinai Peninsula and the Gaza Strip from Egypt and gained control of the West Bank and the eastern sector of Jerusalem from Jordan and the Golan Heights from Syria. In a catastrophic military defeat — which shook the Arab world for many years to come — the Arab nations ceased their fight six days after the war began.