Scholars and policymakers have traditionally seen international law as a framework designed to tame state power. In this insightful book, Hurd argues that international law is actually best understood as a tool of state power—less an externally imposed constraint than a resource that governments employ to authorize and legitimize what they want to do. He arrives at this contrarian view by closely examining the role of international law in contemporary disputes over war, torture, and drones. In Hurd’s portrait, governments pragmatically—and sometimes cynically—interpret international law to suit their purposes. They look for legal arguments that will justify their actions and create a “vocabulary of virtue” to describe their policies. Governments have steadily expanded what qualifies as self-defense, for example, in order to give themselves permission to use force. Nevertheless, Hurd notes, in often small and subtle ways, international law also constructively shapes how states think about and pursue their interests.