The Reagan Administration and Lebanon, 1981–1984

 https://history.state.gov/milestones/1981-1988/lebanon

On October 23, suicide bombers attacked the barracks of the U.S. and French contingents of the MNF, killing 241 American servicemen. The administration believed that the bombings, like the attack on the U.S. Embassy in Beirut that April, were perpetrated by Shi‘i militants linked to Syria’s ally Iran. Reagan responded by adopting a tough policy championed by Shultz and McFarlane, now National Security Advisor. On October 28, he signed NSDD 111, which called for broadening strategic cooperation with Israel and Arab opponents of Syria, reducing Syrian influence over Lebanon’s Druze and Shi‘a, and expanded rules of engagement regarding naval and air support for the Lebanese Army.