A number of journalists considered the Iranian revenge motive ( retaliation for the shooting down of the Iran Air Airbus by USS '' Vincennes '' ) to have been prematurely dismissed by investigators . They drew attention to a comment by former British prime minister Margaret Thatcher in her 1993 memoirs , where she seemed to discount the Libya revenge motive ( for Operation El Dorado Canyon , the 1986 bombing of Tripoli and Benghazi by the United States Air Force ) : Additionally , Abolghasem Mesbahi , former head of Iranian intelligence in Europe , eventually defected and " told German investigators that Iran had asked Libya and Abu Nidal , a Palestinian guerrilla leader , to carry out the attack on Pan Am 103 . " The US Defense Intelligence Agency alleges that Ali Akbar Mohtashamipur ( '' Ayatollah Mohtashemi '' ) , a member of the Iranian government , paid US$ 10 million for the bombing : Part of report , which is dated September 24 , 1989 , cites information acquired at Ft. Meade , MD : and This theory suggests that U.S. Central Intelligence Agency ( CIA ) agents had set up a protected drug route from Europe to the United States — allegedly called '' Operation Corea '' — that allowed Syrian drug dealers , led by Monzer al-Kassar ( who was involved with Oliver North in the Iran-Contra scandal ) to ship heroin to the U.S. using Pan Am flights , in exchange for intelligence on Palestinian groups holding hostages in Syria . The CIA allegedly protected the suitcases containing the drugs and made sure they were not searched . On the day of the bombing , as the theory goes , terrorists exchanged suitcases : one with drugs for one with a bomb
Iran Air Airbus
Iran Air Flight 655
Pan Am Flight 103 conspiracy theories