AbstractInternational relations theory tends to build on the conventional narrative of the Wars of Religion (WoR), which holds it was the irrationality of religious violence that generated the modern international system of pragmatic secular states—resulting in the presumed secularized, rational, and unemotive nature of politics. In contrast, this article reorients our focus to Durkheim's more social view of religion as a community of believers and to the continued role of the sacred and shared emotion/affect in social and political life. Specifically, it examines how modern communities (such as nations) remain constituted by a shared faith in conceptions of the sacred and how the corresponding sense of moral order is central to the enduring pursuit of ontological security. Therefore, it argues that international relations should focus on the perennial struggles over what communities hold sacred and that we can better understand the propensity for (“religious” or “secular”) violence by examining the continual interplay between the sacred, ontological security, and the hermeneutics of morality—with the so-called WoR being the locus classicus of this argument. Historical studies exploring how participants in the WoR navigated such struggles over the sacred thus allow us to explore these dynamics and further conceptualize our understanding of the sacred within modern “secular” politics. The article concludes by examining how the prospect for violence is interrelated with the perennial struggles over the sacred within, and between, political orders—a sentiment that brings into relief some of the hazards accompanying growing intrastate moral polarization and interstate ideological rivalry.