Despite the intensely religious language used by Iranian leaders and soldiers, which permeated war rooms, negotiating tables, battlefields, and streets, the role of religion in the Iran-Iraq War remains underexplored. Some scholars have focused on the pragmatism of Iranian clerical rulers in pursuing the war and ignored their systematic construction of religious legitimacy. Others have examined how religion materially or ideationally constituted the Iranian and Iraqi leaders’ threat perceptions. This article, by contrast, studies how Iranian elites developed and deployed religious narratives according to their internal and external threat perceptions. It uncovers their use of religion ranging from manipulating existing narratives to altering old theologies and crafting new doctrines. Finally, it reveals that the Iranian militant clerics’ instrumental use of religion had unintended theological consequences. I process trace discussions among Iranian political and military elites during the war, their analyses of their own performance on the battlefield after the war, and finally their revealing public disputes and blame-game decades later. Much of the empirical evidence that I have used for this study was not available until recently. It includes Persian books, journals, newspapers, policy papers, memoirs, and interviews by Iranian political and military officials. It is noteworthy that many Revolutionary Guards commanders took advantage of the post-war Iranian version of the G.I. Bill to attend universities. Majoring in social sciences, the humanities, and war studies, many sought to shed academic light on their war-time experiences. Moreover, the intensification of competition between political elites in the past decade has led top officials and military commanders to reveal untold details of their strategic and tactical decisions in an attempt to absolve themselves of wrongdoings. The fruit of the aforementioned academic exercises together with these public debates has been an incredible amount of information, which allows me to reconstruct the war room in Iran.