Conceived as the principal defenders of the 1979 revolution, the Islamic Revolutionary Guard Corps has evolved into an institution with vast political, economic, and military power.

Since the shah’s ouster in February 1979, Iran’s Islamic regime has been propelled by Ayatollah Khomeini’s revolutionary vision and underpinned by its animus toward the United States.

Who calls the shots in Iran on economic policy, security, and domestic calls for reform? A look at the government’s organization chart indicates how complicated the answer is.