World Out of Balance is the most comprehensive analysis to date of the constraints on the United States' use of power in pursuit of its security interests. Stephen Brooks and William Wohlforth overturn conventional wisdom by showing that in a unipolar system, where the United States is dominant in the scales of world power, the constraints featured in international relations theory are generally inapplicable. In fact, the authors argue that the U.S. will not soon lose its leadership position; rather, it stands before a twenty-year window of opportunity for reshaping the international system. Although American primacy in the world is unprecedented, analysts routinely stress the limited utility of such preeminence. The authors examine arguments from each of the main international relations theories--realism, institutionalism, constructivism, and liberalism. They also cover the four established external constraints on U.S. security policy--international institutions, economic interdependence, legitimacy, and balancing. The prevailing view is that these external constraints conspire to undermine the value of U.S. primacy, greatly restricting the range of security policies the country can pursue. Brooks and Wohlforth show that, in actuality, the international environment does not tightly constrain U.S. security policy. World Out of Balance underscores the need for an entirely new research agenda to better understand the contours of international politics and the United States' place in the world order.