Summary This article invites diplomatic scholars to a debate about the identity of diplomacy as a field of study and the contributions that it can make to our understanding of world politics relative to international relations theory (IR) or foreign policy analysis (FPA). To this end, the article argues that the study of diplomacy as a method of building and managing relationships of enmity and friendship in world politics can most successfully firm up the identity of the discipline. More specifically, diplomacy offers a specialized form of knowledge for understanding how to draw distinctions between potential allies versus rivals, and how to make and unmake relationships of enmity and friendship in world politics.