The author investigates a modern proclamation of a holy war by a leading Islamic authority, assessing its legal basis, political intent, and likely effectiveness. He traces classical prescriptions for jihād and the caliph's duties, contrasts them with the fragmentation and secularization of contemporary Muslim states, and explains how authority to wage holy war shifted to territorial rulers. The essay evaluates the practical and propaganda functions of religious appeals in wartime, considers responses among Muslim populations, and argues that changing political structures have constrained traditional instruments of religious warfare.