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.