In The Iranian Revolution Then and Now, Dariush Zahedi assesses the Islamic Republic's potential for revolution through an in-depth, theoretically informed, comparative analysis of the present with 1979 pre-Revolutionary Iran. Zahedi discusses how the potential for a revolutionary coup is based on two things: the inherent defects and vulnerabilities in the regime and the coordinated actions of the social groups and individuals opposed to the regime. He also identifies two 'ideal-typical' forms of revolutionary change (the regime collapses on its own, or, the regime is overthrown). He concludes that the chances for overthrowing the present regime are moderate.