The idea of integrative pluralism offers a promising path for the development of theory in international security and international relations. Instead of either trying to shoehorn all theorising into a single, limited paradigm or giving up entirely on theoretical progress, the integrative pluralist approach calls for bringing diverse approaches together. More precisely, integrative pluralism involves explaining specific phenomena by linking causal processes across multiple layers of reality, and then using the findings to inform broader theoretical constructs such as IR theory paradigms. Elements of the integrative pluralism approach are already visible in the work of mainstream scholars such as Snyder and Katzenstein, as well as of critical scholars such as Sjoberg and Hansen, but the field has tended to overlook these scholars’ efforts at theoretical integration. To more explicitly develop integrative pluralism for our field, this article first draws on critical realist philosophy and social theory. It then illustrates how further steps in this direction might be taken, in particular by highlighting the integrative pluralist aspects of Kaufman's applications of symbolic politics theory to explaining ethnic conflict and war more generally.