Lebanon is unique in the Middle East in having a population roughly equally split between Sunni Muslims, Shiite Muslims and Maronite Christians. In 1971, Palestine Liberation Organization (PLO) militants were expelled from Jordan, many finding a haven – and base for continued activities – in Lebanon. In 1975, initial conflict between PLO and Maronite militias escalated into full-scale civil war, with multiple participants and external provocateurs. In 1982, Israel invaded in response to repeated PLO border incursions, eventually encircling West Beirut, before a UN brokered multinational force was inserted to arrange extraction of PLO militants. At this point, the Lebanese Prime Minister was assassinated (by a Christian, it would later emerge). Israel blamed the PLO and, in mid-September, occupied West Beirut, instructing their Christian Phalange militia allies to clear the Palestinian refugee camps there of PLO. A massacre of thousands of civilians ensued: whether Israeli forces were complicit has been fiercely disputed.
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