The 1982 Lebanon War began on 6 June 1982, when Israel invaded southern Lebanon. The invasion followed a series of attacks and counter-attacks between the Palestine Liberation Organization (PLO) operating in southern Lebanon and the Israeli military that had caused civilian casualties on both sides of the border. The military operation was launched after gunmen from the Abu Nidal Organization attempted to assassinate Shlomo Argov, Israel's ambassador to the United Kingdom. Israeli Prime Minister Menachem Begin blamed Abu Nidal's enemy, the PLO, for the incident, and used the incident as a casus belli for the invasion.

The Palestine Liberation Organization is a Palestinian nationalist coalition that is internationally recognized as the official representative of the Palestinian people. Founded in 1964, it initially sought to establish an Arab state over the entire territory of the former Mandatory Palestine, advocating the elimination of the State of Israel. However, in 1993, the PLO recognized Israeli sovereignty with the Oslo I Accord, and now only seeks Arab statehood in the Palestinian territories that have been militarily occupied by Israel since the 1967 Arab–Israeli War.