Despite the intense media focus on Muslims and their religion during the agitated years following the tragedy of 9/11, few Western scholars or policy makers today have a clear idea of the distinctions between Islam and Islamism. In this important and illuminating book, Bassam Tibi, a senior scholar of Islamic politics, provides a corrective to this dangerous gap in our understanding. He explores the true nature of contemporary Islamism and the essential ways in which it differs from the religious faith of Islam, founded in 610. Contemporary Islamism, or Islamic fundamentalism, is distinct from - although an outgrowth of - traditional Islam, Tibi asserts. Drawing on research in twenty different Islamic countries over the course of three decades, he describes Islamism as a political ideology based on a reinvented version of Islamic law. In separate chapters devoted to the major features of Islamism, he discusses the Islamist vision of state order, the centrality of anti-Semitism in Islamist ideology, Islamism's incompatibility with democracy, the reinvention of jihadism as terrorism, the invented tradition of shari's law as constitutional order, and the Islamists' confusion of the concepts of authenticity and cultural purity. Tibi's concluding chapter applies elements of Hannah Arendt's theory to identify Islamism as a totalitarian ideology.