iThe Israelis wished to remain in Beirut until they could achieve two political objectives: the expulsion of the PLO and the replacement of Syrian hegemony over Lebanon by the hegemony of Israel. The 2d objective was to be achieved through the election, by the Lebanese Parliament, of Israel’s ally, Bashir Gemayel. On August 23, 1982, while the PLO evacuation of West Beirut was in progress, Bashir was elected President of Lebanon, by a bare quorum of the Parliament. The Israeli elimination of the Syrian factor from Beirut had left the field free to the Maronites. In tune with Syria, many prominent Lebanese politicians - belonging to the Sunni, Shi’i and Druze communities - denonced the holding of such an election in time of occupation.
The election of Bashir was the high point of Sharon’s Grand Design for Lebanon. However, instead of aligning with Israel, Bashir tried to distance himself from Israel, and remained isolated and impotent in Lebanon, outside his home base. He tried to recover from the Druze mountain villages in the Shouf, formerly belonging to the Christians. The Druze drove back his forces without difficulty, captured other Christian villages, and massacred their inhabitants, in accordance with the customary practice of the feuding clans.
On 9/14/82, a bomb demolished a party headquarters building n East Beirut, at which Bashir was speaking. 26 people, including Bashir, were killed.
The immediate response of the Israelis, on 9/15, was to occupy West Beirut “in order to protect the Muslims from the revenge of the Phalangists.” In fact what the IDF didpected nests of * fedayeen * combatants. What the Christian soldiers then did, in accordance with the general practice of the Lebanese civil wars, was to take indiscriminate vengeance on the whole population perceived as hostile. Sharon’s and Eytan’s motive was to spare Israeli casualties, in a war that had already cost more than 400 Israeli lives. They chose to disregard the direct threat to the lives of Palestinian noncombatants, which followed from the use of the armed Maronites.
The massacre was an “ordinary” one by Lebanese standards, one of a series of vendetta butcheries which had been going on sporadically since the outbreak of the Civil War in the mid-70s. Where it was far from ordinary was that those who carried it out had been unleashed at the command of senior Israeli officers, in an area which Israeli forces had entered in order “to prevent any possible incident and to secure quiet,” in the wake of the assassination of Bashir.
Source * The Siege * (1986) by Conor Cruise O’Brien