After the Suez-Sinai war Arab nationalism increased dramatically, as did demands for revenge led by Egypt's president Nasser. The formation of a united Arab military command that massed troops along the borders, together with Egypt's closing of the Straits of Tiran and Nasser's insistence in 1967 that the UNEF leave Egypt, led Israel to attack Egypt, Jordan, and Syria simultaneously on June 5 of that year.

The war ended six days later with an Israeli victory. Israel's French-equipped air force wiped out the air power of its antagonists and was the chief instrument in the destruction of the Arab armies.

The Six Days War left Israel in possession of Gaza and the Sinai Peninsula, which it took from Egypt; Arab East Jerusalem and the West Bank, which it took from Jordan; and the Golan Heights, taken from Syria. Land under Israel's jurisdiction after the 1967 war was about four times the size of the area within its 1949 armistice frontiers. The occupied territories included an Arab population of about 1.5 million.

The occupied territories became a major political issue in Israel after 1967. The right and leaders of the country's orthodox religious parties opposed withdrawal from the West Bank and Gaza, which they considered part of Israel. In the Labor Alignment, opinion was divided; some Laborites favored outright annexation of the occupied territories, others favored withdrawal, and some advocated retaining only those areas vital to Israel's military security. Several smaller parties, including the Communists, also opposed annexation. The majority of Israelis, however, supported the annexation of East Jerusalem and its unification with the Jewish sectors of the city, and the Labor-led government formally united both parts of Jerusalem a few days after the 1967 war ended. In 1980 the Knesset passed another law, declaring Jerusalem “complete and united,” Israel's eternal capital.

The 1967 war was followed by an upsurge of Palestinian Arab nationalism. Several guerrilla organizations within the Palestine Liberation Organization (PLO) carried out guerrillas attacks on Israeli targets, with the stated objective of “redeeming Palestine.” guerrillas attacks on Israelis targets at home and abroad unified public opinion against recognition of and negotiation with PLO, but the group nevertheless succeeded in gaining widespread international support, including UN recognition as the “sole legitimate representative of the Palestinians.”.