Political map of the Eastern Mediterranean 18 August 1982 (1982 Lebanon War): In June 1982, following more clashes with the Palestine Liberation Organization (PLO) (PLO in Lebanon), Israel launched a second invasion of Lebanon, rapidly advancing as far as Beirut, where it trapped both PLO and Syrian forces (1982 Lebanon War). After a two-month siege (Siege of Beirut), the PLO agreed to evacuate Lebanon and Israel pulled back to the Awali River, where it remained in occupation of a third of the country until 1985.