It was social liberalism masking a particularly virulent and corrupt regime under the Shah. The greatest mistake the West made in dealing with modern Iran was to support the coup against Mossadeqh; it ushered in a period of political oppression that even CIA admitted was unsustainable, and which led inexorably to the Bazaari-Clericalist revolution. (Khomeini's supporters weren't the only anti-establishment revolutionaries, but they seized the reins of power first and then began systematically reducing the liberal and Marxist opposition.)