This paper will examine the profound impact of the Iran-Iraq War on Iran’s security apparatus and the country’s place in the world through a comprehensive assessment of the roles and relationship of Iran’s two armed forces, the Islamic Revolutionary Guards Corps (IRGC) and the regular military (Artesh), as they evolved during the conflict. It is based on an in-progress book chapter for a new edited volume on the histories and legacies of the Iran-Iraq War. The paper will utilize and juxtapose the IRGC’s sources on the war, which have received little but growing focused scholarly attention, with those of the Artesh, and critically analyze their narratives by integrating a range of secondary and other primary sources. In particular, the paper will examine the impact of Iran’s 1979 revolution on the two militaries’ institutions and ideologies and the ramifications thereof for how the forces viewed and prosecuted the war. In some respects, and especially initially, the revolution affected the forces in very different ways. While the Artesh was maligned and eviscerated as a result of its association with the deposed regime and for what was seen as an insufficiently Islamic-revolutionary outlook, the IRGC was wholly borne of the revolution and was championed as its vanguard and the embodiment of its ideology. Those divergent revolutionary experiences generated distinct, often discordant, approaches to warfighting, hampering Iran’s ability to prosecute the conflict. However, and although differences persisted, the joint experience of fighting the war brought the forces closer together both institutionally and ideologically. The Artesh was revived and re-institutionalized as the IRGC transformed from a revolutionary militia into a more formal and professional military more akin to the Artesh. Similarly, the Artesh effectively adjusted to the revolutionary landscape as the IRGC adopted more “classical” approaches to prosecuting the war. Such an assessment, the paper argues, provides significant insight into the complex and dynamic connections between war and revolution in and beyond Iran.