What exactly does Islamism mean? And what explains its violent expansion in recent decades? Are there similarities between Islamism and classical totalitarian regimes and ideologies? Will it fail, as those regimes did in Nazi Germany and the Soviet Union; or can it adapt effectively to changing realities? What are the fundamental strengths and weaknesses of the Islamic project? Addressing these questions within a context both historical and global, Mehdi Mozaffari provides an important new framework for understanding the full impact of Islamism in the Middle East and beyond.