The US Embassy in Beirut was bombed in April 1983, six months before the Marine Barrack, not Army barracks, were bombed. Death Before Dishonor uses these incidents in the same manner the Heartbreak Ridge used the invasion of Grenada.
The suicide car bombing in this film was probably one out of hundreds of typical incidents in such a troubled spot. Then the abduction of the Colonel (Brian Keith) had a composite incident with the factual abduction of U.S. Marine Lt. Colonel Richard Higgin's during a U.N. peacekeeping mission in 1987. The movie character was rescued, while Higgins was tortured and executed.
US military in Lebanon AKA "Jamal" the event with the suicide car bomber is based on a true event in Beirut 1983 but it was an American army barrack not an American embassy.