The Iran-Iraq war also called “The Imposed war” by Iranians is considered the longest conventional war in modern times. Given the number of associated deaths and injuries (soldiers and civilians) it is also one of the bloodiest wars in modern history. It started more than thirty-five years ago based on regional rivalry and a desire for territorial acquisition. Despite Saddam Hussein’s belief that it would be an easy victory for him, the Iran-Iraq war lasted eight brutal years and resulted in wide scale devastation on both sides. As a result, this war has had and continues to have an immense impact on Iran, Iraq, as well as the greater Middle East. This is related to the use of ideology (religious sectarianism) as a tool for propaganda and the propagation of internal and external support. More specifically, the strategic use of Sunnism by Iraq and Shia’ism by Iran, assisted each nation to strengthen its position during the war. For example, the Sunni versus Shia framework was used as the pretext by Saddam Hussein for the invasion of Iran and the war despite his political and geostrategic aspirations. The Sunni versus Shia framework that emerged, not only impacted the war, but also evolved into the sectarian struggles we see today. It ultimately put Shia Iran and Sunni Saudi Arabia at odds with one other and created the foundation for ongoing sectarian conflict between the two nations. Similar to the Iran Iraq war, sectarianism is being used as a tool to achieve political and geostrategic advantages and ultimately regional dominance. The long-term impact of the sectarian fault lines of the Iran-Iraq war can be seen today across the Muslim world, including in Syria, Iraq and Yemen. These countries have been torn apart along deepening fault lines and the lives of citizens have been severely impacted as a result. As such, it is important to have a comprehensive understanding of the role that sectarianism had in mobilizing forces and support during the war for both Iran and Iraq, as well as the impact this strategy continues to have in the Middle East. This paper will examine the Iran-Iraq war, including its evolution, its framing, the role of foreign influence, as well as a brief examination of the current sectarian conflict in a post Iran-Iraq war context.