A growing number of scholars have sought to re-centre emotions in our study of international politics, however an overarching book on how emotions matter to the study of politics and war is yet to be published. This volume is aimed at filling that gap, proceeding from the assumption that a nuanced understanding of emotions can only enhance our engagement with contemporary conflict and war. Providing a range of perspectives from a diversity of methodological approaches on the conditions, maintenance and interpretation of emotions, the contributors interrogate the multiple ways in which emotions function and matter to the study of global politics. Accordingly, the innovative contribution of this volume is its specific engagement with the role of emotions and constitution of emotional subjects in a range of different contexts of politics and war, including the gendered nature of war and security; war traumas; post-conflict reconstruction; and counterinsurgency operations. Looking at how we analyse emotions in war, why it matters, and what emotions do in global politics, this volume will be of interest to students and scholars of critical security studies and international relations alike.