In the wake of the Iranian Revolution of 1979, the country’s new leaders worked to reshape Iran’s political identity. They focused particularly on rejecting the symbols that had defined the Iranian polity under the rule of the shah and by making Islam its central pillar. For Ayatollah Khomeini and his allies, nationalism was closely associated with the monarchy and was therefore suspect. However, and despite Islam’s centrality, nationalism remained a driving force in Iran under the Islamic Republic. Iraq’s September 1980 invasion of Iran had much to do with that. On the one hand, the attack by a foreign power ignited deep and strong patriotism throughout Iranian society. On the other, the leaders of the Islamic Republic were faced with the task of mobilizing the population to defend the country and to prosecute what became a drawn-out conflict. They therefore capitalized on the rising tide of nationalism to sustain the war effort. This paper will examine the nature and significance of nationalism in the Islamic Republic of Iran following the Iraqi invasion and during the ensuing eight years of the Iran-Iraq War. In particular, the paper will analyze how the Islamic Revolutionary Guards Corps (IRGC) and other leaders of the new regime portray nationalism and its relationship to the ideology of the Islamic Revolution. The examination will be based on a textual analysis of publications produced by the IRGC and of statements made by Revolutionary Guards leaders about the war, along with related sources produced by the Iranian government. The IRGC publications consist of analytical studies of the conflict in Persian, which have received hardly any scholarly attention. They provide a rich and detailed account of the war that sheds new light on both the conflict and on the IRGC, and that demonstrates the importance the Guards attach to shaping the history and memory of the war. Those sources reveal that concepts and terms traditionally associated with nationalism figure prominently in the way the Guards define and describe the war and the Islamic Republic of Iran more generally. In many cases, nationalist terms are interwoven with references to Islam, the Islamic Revolution, and the Islamic revolutionary ideology of Ayatollah Khomeini, a fact which reflects the synthesis and concordance of the various strands of the Islamic Republic’s politics and ideology.