In 1982, in a widely criticized move, Begin's government invaded Lebanon because of the constant terrorist attacks over Israel's northern border. This began the Israeli-Lebanese war, which lasted until 1985 (when Israel retreated to a narrow strip of land in Northern Lebanon known as the Security Zone). Although Israel retreated from that land in 2000, the Lebanese terror organization Hizballah is still effectively in a state of war with Israel, and holds Israli prisonners.
Begin himself retired in August 1983, deeply disappointed and depressed by the war, his spouse's death and his own illness. He died in Jerusalem in 1992.