This article argues that systematic rape should be conceptualized not only as a war crime, but also as a destructive and increasingly deployed war weapon. As such, rape becomes a subject of arms control and thus directly relevant to security studies. Consequently, I argue that international relations should consider rape as a weapon of war for two major reasons. First, the categorization of rape as a weapon of war fits with core disciplinary theoretical definitions and assumptions. Namely, rape as a weapon of war compromises state security, operates in a conception of power defined as material/“power-over”/zero-sum, and corresponds with a rational actor model. Second, although wartime rape has often been marginalized as a “women's issue,” empirical evidence persuasively demonstrates how this categorization is incomplete; rather, women, girls, men, and boys all suffer direct and/or indirect consequences from the increasing prevalence and brutality of this weapon's deployment. Overall, the article maintains that excluding rape from security studies precludes comprehensive, accurate analysis within areas of theoretical and practical concern to IR. Thus, I conclude by suggesting avenues of research, from diverse theoretical perspectives, that may persuade IR scholars to view rape as an increasingly relevant and analytically rich topic of study.