Is just war thinking flexible enough to address the unique ethical problems of contemporary warfare? In this book, Amy E. Eckert takes up the problem of military privatization, asking whether the just war tradition can adequately address the ethical problems posed by states’ increasing reliance on private military companies (PMCs). Such corporations—including the now defunct Blackwater—provide a variety of services to the states that hire them, from logistics to combat.

A skeptic might ask why PMCs should prompt revisions of the tradition, since canonical just war thinking (whose authorities include Thomas Aquinas and Francisco de Vitoria) developed in an era when mercenaries were frequently employed. Eckert’s cogent response is that two very modern assumptions motivate contemporary just war thinking. First, Eckert argues that contemporary just war thinking is heavily indebted to the international law of war, which is itself a product of the post-Westphalian state system. Contemporary just war thinking’s statist orientation is challenged by PMCs’ disruption of the state’s monopoly over the legitimate use of force. Similarly, the in bello criteria, in Eckert’s view, developed in their present form only after the rise of the sovereign state and presume a clear distinction between state actors (national mili