In 1967 Colonel Nasser, Egypt's leader, attempted to close the Tiran Straits to prevent ships entering Israel's port of Eilat. On 5 June Israel retaliated with air strikes, destroying Egyptian airfields. Within a week Israel had seized the Sinai Peninsula and the Gaza Strip from Egypt, the West Bank from Jordan and the strategic Golan Heights from Syria, resulting in a decisive Israeli victory.
Britain, concerned about oil supplies and the reopening of the Suez Canal, helped negotiate peace via the UN Security Council. Resolution 242 was brokered on 22 November 1967 and required that:
Israel and a number of the Arab states accepted the resolution, but Syria did not.
In 1970 the British Foreign Secretary, Alec Douglas-Home, pressed for a Middle East settlement that returned territorial boundaries to the position before 1967.
On the Jewish holy day of Yom Kippur (the Day of Atonement), 6 October 1973, Egypt and Syria simultaneously attacked Israel. The Egyptian and Syrian armies initially made gains, but by the third week of October these had been reversed. In another swift retaliation, Israel occupied Egyptian territory south west of the canal, and increased the occupied area in the Golan Heights.
On 11 November 1973 Israel and Palestine signed a ceasefire. The US and Soviet Union convened a peace conference in December but it was inconclusive. The British government remained committed to the existence of a secure Israel, but believed that the return of occupied territories was necessary for lasting peace.