Are violent jihadis an enduring feature of modern international affairs, or do they hold in their own doctrines the seeds of self-destruction? Historical precedent suggests the latter. Jihadi ideologues have formulated an individualist-centered Islam to mobilise Muslims far and wide, youthsabove all, to join a global jihad. However, the duty and right to an individually initiated jihad constitutes just one side of this do-it-yourself Islam; the other is the duty to protect the purity of doctrinal beliefs against any perceived deviation by even their fellow jihadis. This book explores the religious philosophy underlying jihadism, as set against the background of the Kharijites, the first counter-establishment movement in Islam, whose idealistic and individualistic practice of Islam inevitably led them to deploy takfir against each other and thereby toself-destruct. By investigating the links between Kharijism and jihadism, Lahoud argues that the same doctrinal beliefs that appear to unite today's jihadis will also be the cause of their downfall.