At this point, only the short-term future of Iran's clerical regime remains in doubt. The current protests could be repressed, but the unelected institutions of priestly rule have been fatally undermined. Though each aspect of the Islamic Republic has its own dynamic, this is not a regime that can last many more years.
When it comes to repression, Iran has a spectrum of security instruments that can be used synergistically. The national police can take care of routine crowd control; riot-police units can beat some demonstrators in order to discourage others; the much more brutal, underclass Basij militiamen enjoy striking and shooting affluent Iranians; and the technical arm of the regime can block cellular service to disrupt demonstrations, as well as stall Internet services. MORE on the Wall Street Journal