Glennon has long been an eloquent critic of traditional approaches to international law derived from idealistic, universalistic, and moralistic tenets. About the legality of the U.S. invasion of Iraq, for example, he has advanced a decidedly skeptical view of international law. In this landmark book, Glennon lays out his alternative take. As he sees it, international law is simply what states make of it, and it matters only to the extent that states want it to. Whereas law within states is ultimately upheld through coercion, international law is based on consent: states must choose to abide by the strictures and obligations of international law, and they can just as easily withdraw their consent. In Glennon's hands, international law is shorn of its transcendent characteristics and becomes more like the run-of-the-mill rules and agreements that make up international relations. Indeed, when Glennon turns to the thorny question of law and the use of force, his discussion will look familiar to political scientists who study international institutions, legitimacy, power, and the rational choices of states. In the end, Glennon argues that since the United States is a party to more treaties than any other state, it has a special stake in the continuity and stability of international agreements -- a view the traditional international legal thinkers would surely affirm as well.