In May 1967, Nasser received false reports from the Soviet Union that Israel was massing on the Syrian border.
[20] Nasser began massing his troops in the Sinai Peninsula on Israel's border (May 16), expelled the UNEF force from Gaza and Sinai (May 19), and took up UNEF positions at
Sharm el-Sheikh, overlooking the
Straits of Tiran.
[21][22] UN Secretary-General
U Thant proposed that the UNEF force be redeployed on the Israeli side of the border, but this was rejected by Israel despite U.S. pressure.
[23] Israel reiterated declarations made in 1957 that any closure of the Straits would be considered an act of war, or a justification for war.
[24][25] Nasser declared the Straits closed to Israeli shipping on May. 2223. On 27 May he stated "Our basic objective will be the destruction of
Israel. The Arab people want to fight."
[26] On May 30, Jordan and Egypt signed a defense pact. The following day, at Jordan's invitation, the Iraqi army began deploying troops and armored units in Jordan.
[27] They were later reinforced by an Egyptian contingent. On June 1, Israel formed a National Unity Government by widening its cabinet, and on June 4 the decision was made to go to war. The next morning, Israel launched
Operation Focus, a large-scale surprise air strike that was the opening of the Six-Day War.