This essay explores the conceptualization of warfare in Romanticism. The focus is on two plays by Heinrich von Kleist, Penthesilea and Prince Friedrich von Homburg. I begin by discussing Carl von Clausewitz's influential understanding of conflict and the problems that arise when he attempts to explain the interdependence of warring parties. I go on to argue that in Kleist's dramas war is a competition between different languages of authority. When no coherent paradigm of agency emerges from this contest, the right to wage war is revealed to be anything but a guarantee that one knows how to do so.