Posen has written the most challenging critique yet of the United States’ post–Cold War grand strategy of global engagement. According to Posen, U.S. liberals and neoconservatives both see a multitude of threats facing their country that call for elaborate American-led efforts at security cooperation and power projection. In their view, Washington must remain the world’s dominant military power, build alliances, deploy forces around the world, manage global institutions, and be ready to intervene anywhere to ensure stability and promote liberal democracy. But Posen advances a much narrower, classical realist definition of U.S. security interests: sovereignty, territorial integrity, and the safety of the homeland. The liberal hegemonic order is built around Washington’s ability and willingness to enforce global rules and protect allies, but Posen argues that this undertaking is too costly and unsustainable. Yet how does one determine the proper price of “stability” or determine if the presence of U.S. forces in Asia and Europe prevents costly wars or provides Washington with political influence in other policy areas? Posen’s strong argument is that this dependence on U.S. power increases Washington’s propensity to make costly mistakes. But in the absence of a system that relies on Washington for stability, what would discipline American power and prevent the United States from pursuing self-destructive ideological crusades or risky overseas adventures? The trouble is that what Posen is proposing is really a strategy of disengagement, which comes with its own dangers. In reality, a more restrained United States would be one that is even more deeply bound to the international community through its leadership of global institutions and alliances.