The leader of the PLO , Yasser Arafat , established close collaboration with the Romanian Securitate service and the Soviet KGB in the beginning of the 1970s . The secret training of PLO guerrillas was provided by the KGB . However , the main KGB activities and arms shipments were channeled through Wadie Haddad of the DFLP organization , who usually stayed in a KGB dacha BARVIKHA-1 during his visits to Russia . Led by Carlos the Jackal , a group of PFLP fighters accomplished a spectacular raid on OPEC headquarters in Vienna in 1975 . Advance notice of this operation " was almost certainly " given to the KGB
raid on OPEC headquarters
OPEC siege
State-sponsored terrorism