American foreign policy appears to have taken a sharp unilateral turn. A half century of U.S. leadership in constructing an international order organized around multilateral institutions, rule-based agreements, and alliance partnerships seems to be giving way to an assertive unilateralism. But how deeply rooted is this unilateral turn? Is it an inevitable feature of America's rising global power position? This article argues that the United States is not doomed to shed its multilateral orientation. Unipolar power provides new opportunities for the United States to act unilaterally, but the incentives are actually quite complex and cross-cutting; and these incentives arguably make multilateralism more rather than less desirable for Washington in many policy areas.