The Sunni-Shi'a sectarian split has in recent years been accused of being the primary cause of the on-going violence in the Middle East. Here I describe the complex relationship this schism has with politics in the region. I explore this phenomenon at three different levels of analysis: the local, regional and international. I argue that in terms of motivating political actors, religion and politics form a hierarchy of importance. At the local level religion has the strongest effect, and is where we see the greatest level of violence. At the regional level I show that politics and religion appear to be of commensurate import. At the international level of Great Power politics religion plays the weakest role in motivating actors, however owing to what I term the 'Sectarian Lifecycle', international affairs still acquire a religious significance. This is due to high media consumption in the Middle East that means international affairs directly touch local affairs in real time and as such have the potential to trigger violence. I also show that at all levels the Sunni-Shi'a divide generates a tension between the short-term and long-terms goals of political actors. Finally this article argues that US-Iranian engagement would make it possible to dampen down the sectarian fire in this conflict without recourse to war.