This week in 1983 Iranian backed Shiites bombed the U.S. Marine barracks in Beirut, killing 299 Marines and French soldiers.
The Marines had been sent as part of an international peacekeeping force in the wake of the Lebanese civil war. Iranian-backed Shiites who later formed Hezbollah carried out the attack:
Although no group has ever made a serious claim of responsibility for the attack, perpetrators were later fingered. The actors that carried out the deadly bombings were elements that two years later would be central and founding members of Hezbollah, a group well-known to be funded, armed and trained by Iran.
One of the central actors in the bombing, Imad Mughniyeh, was secretly indicted several years later in the United States for his role. Mughniyeh, who would later become known as an arch-terrorist of sorts, has been tied to and indicted in relation to some of the largest terror attacks on Jews and Americans carried out prior to September 11, 2001.
The French retaliated by bombing Iranian Revolutionary Guards in Lebanon. The U.S. never retaliated. Mughniyeh was killed in Damascus in 2008, reportedly by the Israelis although it’s never been proven.