Revolutions
I've been reading a few sources (including Wikipedia) this morning, and I've picked out two points from the general Conventional Wisdom:
A) Mossadeq was very pro-Western, and in no way leaning toward the Soviets as far as Cold War alliances were concerned, so there was no motivation for the CIA actions except oil interests
B) The Shah's pro-Western views were what drove the mullahs to revolt and take over the country.
I have a lot of difficulty working both of these together into the foggy premise that if we had left Iran alone, the Islamic revolution would never have happened.