This contribution examines how the critical potential of research on peace in International Relations has been simultaneously marginalized and transformed. It briefly traces the evolution of peace research, as well as choices, contestation, and breaks in the construction (and "disciplining") of peace and conflict research. It then focuses on two epistemological and normative choices that occlude the emancipatory potential of peace research and marginalize certain approaches to the study of the causes of war and conditions of peace. In a more positive vein, it illustrates, with examples from recent research, where potentially emancipatory or transformative scholarship on building peace has migrated.