As this new century progresses, America will not be able to sustain the global preponderance it enjoys today. Over time, a unipolar international system will give way to a world of multiple centers of power, and a more diffuse concentration of power could have adverse global consequences. Although scholars disagree about whether bipolar or multipolar systems are more stable, most agree that both are less stable than unipolar systems. Power in Transition addresses the question of how to prepare for the waning of American hegemony and the resultant geopolitical consequences. Can the impending transition to multipolarity be managed peacefully? Is systemic change possible without war? Under what conditions and through what causal mechanisms can power transitions occur peacefully? The authors identify past cases of peaceful transition, seek to understand which variables enable major power shifts to occur without war, and draw lessons on how the international community can best manage the coming transition to multipolarity. The analysis focuses on three core issues: how contenders for primacy come to see one another as benign; how they negotiate a mutually acceptable international order; and how they legitimize that order. The authors also reflect on whether the nature of systemic change is itself changing because of social learning and underlying shifts in the character of the international system. Case studies examined include the Concert of Europe, Anglo-American rapprochement at the end of the nineteenth century, and ASEAN. This volume helps fill a major gap in the literature on peaceful systemic change. It also contributes to efforts within the scholarly and policy communities to establish the means by which peaceful management of coming change in the international system may be achieved.