give the u.s. pause as it negotiates with the iran's leadership. >> past three iranian ministers of defense, including the current one select ad few months ago, all have peacekeepers blood on their hands. are leading the iranian lockstep march for the acquisition of nuclear weapons. >> reporter: the marine barracks bombing was a turning point in the middle east when radical islamists realized the power of suicide truck bomber. usama bin laden referred to it as a model for future attacks. >> the fact that what happened is that the multinational peacekeeping force that had been deployed to beirut to keep the peace in a war-torn civil war all withdrew. the united states, the italians, the french, the brits, everybody pulled out and that was the lesson that was learned by radical islamic terrorists in the aftermath of both embassy bombings and the marine