How should we understand ISIS today? Despite its territorial defeat in Iraq and Syria in 2019, ISIS has evolved and expanded globally. This book is the most comprehensive study of ISIS to date, benefitting from Arabic sources previously unavailable to an English-speaking audience. Renowned scholar and political philosopher, Azmi Bishara, stresses the need to place ISIS in its historical, social and political context - rather than primarily its Salafi ideology - in order to understand its rise and expansion. The book explains ISIS in terms of both historical and recent political events, including the Six-Day War of 1967, the decline of Arab nationalism, sectarian politics, the outbreak of civil war in Iraq and Syria and the decline of the central state. The book counters the view of some Western researchers that a Sunni environment was conducive to ISIS's control in Syria and Iraq and also separates the rise of the organization from its exploitation of religious texts. The final chapter defends Islamic civilization against those who hold Islam responsible for ISIS ideology by reviewing and deconstructing significant jihadi Salafi texts and showing the extent to which Salafi thought departs from Islamic thought and culture.