Abstract
This paper reexamines quantitative indicators of national economic and military power since 1820 and discusses their meanings for the trajectory of power concentration in the contemporary world-system. We discuss the causes of U.S. hegemonic decline and consider what the consequences are likely to be for global governance in the future. Using the evolutionary world-systems approach to understanding cycles of centralization and decentralization in interpolity systems, we consider the similarities and differences between the hegemonic declines of the United States of America and the United Kingdom of Great Britain. We also discuss the possibility of another round of U.S. hegemony and how revitalization of U.S. manufacturing could allow the U.S. to once again play a more central role in world politics. We discuss how this could happen and the factors that are likely to prevent it from happening. We also discuss the likelihood of a period of hegemonic rivalry, conflict, ecological disasters and chaos in the next few decades and the possibility that a collectively rational and democratic global commonwealth might emerge.