Foreign Policy explains the hesitancy of Western governments to fully "back" the
Mousavi moment:
It was Mousavi, after all, who was at the center of the Iran hostage crisis and remains complicit in an operation he commended as "the beginning of the second stage of our revolution." And it was Mousavi who was the protégé of Ayatollah Ruhollah Khomeini (chief architect of the Iranian Revolution and founder of theocratic Iran), a former member of Hezbollah's leadership council, sworn enemy of Israel, and a prime minister under whose watch thousands of political prisoners were massacred in 1988. And finally, it was Mousavi who initiated Iran's nuclear program in the 1980s and likely would be intent on carrying through Iran's nuclear ambitions, the foremost issue central to any improvement in relations with the West.