The really sick thing is that the terrorist swine at the "Islamic Association for Palestine" were whining about it at the time as an attack on Muslims and have never apologized. The link I gave you STILL works, it's been over a year and they STILL have this link on their page, whining about the FBI's desperate last-second attempt to stop 9/11.
Clarridge waged psychological warfare against Nidal, until every one of his follower's loyalty was suspect in the eyes of their leader. Finally, in 1987, Nidal executed 300 of his own hard-core operatives. As Clarridge put it, "Abu Nidal's paranoia, fed by our crusade against him, caused him to destroy his organization."
It took Clarridge more than a few years to bring it to that point, but it was definitely an effective tactic. (And one of the few CIA successes against terrorism.)