The CIA 's prime source in Lebanon was Bashir Gemayel , a member of the Christian Maronite sect . The uprising against the Maronite minority blinded the CIA . Israel invaded Lebanon , and , along with the CIA , propped up Gemayel . This got Gemayel 's assurance that Americans would be protected in Lebanon . Thirteen days later he was assassinated . Imad Mughniyah , a Hezbollah assassin would target Americans in retaliation for the Israeli invasion , the Sabra and Shatila massacre , and the US Marines of the Multi-National Force for their role in opposing the PLO in Lebanon . On April 18 , 1983 , a 2,000 lb car bomb exploded in the lobby of the American embassy in Beirut , killing 63 people including 17 Americans , and 7 CIA officers , including Robert Ames , one of the CIA 's best Middle East experts . America 's fortunes in Lebanon would only suffer more as America 's poorly-directed retaliation for the bombing was interpreted by many as support for the Christian Maronite minority . On October 23 , 1983 , two bombs ( 1983 Beirut Bombing ) were set off in Beirut , including a 10-ton bomb at a US military barracks that killed 242 people . Both attacks are believed to have been planned by Iran as a way of Mughniyah
Sabra and Shatila massacre
Sabra and Shatila massacre
Central Intelligence Agency