Maybe we could repeat this sequence:
"Because of the damage to U.S. credibility, the Reagan administration--at Lebanon's request--sent 1,800 Marines back into Lebanon on September 29 as part of a multinational force that included troops from Britain, France, and Italy. The force was initially to act as a peace-keeping buffer between the Israelis and everyone else. In that environment of civil disorder, bombings, and kidnappings, the mission of the U.S. Marines was unclear. They were harassed by the Israeli forces and opposed by other factions. Particularly ominous was the activity in the Bekaa Valley of Iranian guerrillas and Lebanese Shi'ites, such as the Hezbollah group, who were sympathetic to the Iranian regime. In April 1983 one of those groups, the Islamic Jihad, claimed responsibility for the bombing of the U.S. embassy in Beirut in which 46 people were killed.
In August Israel partially withdrew to the south, leaving the Marines in the crossfire between Lebanese factions and removing their reason for being there in the first place. The Marines suffered casualties from Druze artillery--although it is not clear that the shelling was intentional--and the U.S. Sixth Fleet off the coast countered by firing shells the weight of Volkswagens at Druze positions. U.S. aircraft flew bombing missions as well. The United States had clearly taken sides in the Lebanese civil war.
The consequences of U.S. intervention became all too apparent on October 23 when a truck filled with explosives entered the Marine headquarters at Beirut airport. The resulting blast killed 241 Marines. By February 1984 Reagan had abandoned the intervention in Lebanon and withdrawn the surviving Marines.(189)"
http://www.cato.org/pubs/pas/pa-159.htmlIn fact, even though the source is the Cato Institute, the entire article is a good read if you want background on the middle east that is not the standard narrative.