Scholars of religion in Indonesia have consistently maintained that it is an exceedingly complex phenomenon not given to straightforward analysis or generalizations. The complexity of the topic is arguably captured in the concept of aliran (streams, referring to the different currents of Islam in Indonesia), which since its introduction to Indonesian studies by the anthropologist Cliffor Geertz has continued to provide a useful point of entry to the analysis of social and political trends in the country. Originating in Geertz's study of Indonesian Islam, scholars of Indonesia had traditionally set great store by the notion of aliran, which speaks to the existence of multiple, dynamic, oftentimes competing streams that define the variegated nature of Indonesian society and politics. Even though the veracity of the concept has in recent times been critiqued and challenged, the evolution of autonomous regional and local histories and identities over time has doubtless also contributed to this diffused heterogeneity.

Because Indonesian society has by and large managed to accommodate this diversity, it has acquired a reputation for pluralism and tolerance. The accuracy or aptness of this characterization, however, has been a matter of considerable debate. This debate notwithstanding, the main analytical assertion here is that issues of what constitutes the nation in terms of who should be included or excluded, and on what grounds, remain contested at the geographical as well as confessional margins, and the frequent occurrence of various forms of religious tension and conflicts serves as a prescient reminder of this. Bearing this in mind, it is with caution that this chapter wades into the debate by focusing on what it is that is “religious” about religious conflicts in Indonesia, and how to conceptualize it against broader themes that define the process of negotiation and renegotiation of nationhood.

The study of communal or sectarian violence in Indonesia has long been a rich analytical and empirical field. An extensive literature is now available that explores the complex and multifarious dynamics that account for violence in Aceh, Papua, Sulawesi, Maluku, North Maluku, and Kalimantan. A careful scrutiny of this scholarship reveals a multiplicity of analytical frameworks and explanatory variables that includes ethnic identity, opportunism on the part of elites at local and national levels, terrorism and ideological and theological extremism, political transition as a result of the collapse of President Suharto's New Order government, resource competition, and criminality.