In the last few years, sectarianism has become a word encountered every day in almost all forms of media, in connection with recent events in the Middle East. Many political commentators and scholars have adopted the term without explicitly defining it because its meaning appears to be implicitly understood. However, it is clear upon even a cursory examination that the term, sectarianism, in its various contexts both in the Middle East and elsewhere in the world refers to rather different concepts, even when the field of examination is confined to the twentieth century. So what do we mean when we talk about sectarianism? And perhaps more importantly, how useful is it as a “category of analysis,” to borrow Frederick Cooper’s phrase? Through an analysis of the Shi’i press in Lebanon and Iraq in the interwar period, this paper will argue that sectarianism constitutes neither a clear category of practice nor a useful category of analysis in the Iraqi and Lebanese contexts because it has no independent political definition apart from its relationship with the ideology of nationalism, and that the two are in fact intimately connected concepts in the ideology of the modern nation-state. As a result, the use of sectarianism as a category of analysis in scholarship on the Middle East has reified both the concept itself and that of the nation-state as the only legitimate form of political organization. The first half of this paper will briefly trace the definitions of sectarianism and the uses of the term in contemporary scholarship on the Middle East, with a particular focus on the wide range of definitions currently in use that blur the boundary between category of analysis and category of use. The second half will present a new model for exploring community relations in the Middle East, focusing specifically on the Shi’i communities of Iraq and Lebanon before World War II.