Four areas in the world are at present or potentially major power centers: the United States, the Soviet Union, Western Europe, and Communist China. In all four, productivity is on the increase and the political system performs relatively well its integrating and decisionmaking functions. Despite major differences among them which need not be examined here and various weak spots which might reverse trends, these four areas are likely to be in a position to play major roles in political, economic, and cultural international affairs in the coming decade. In contrast, the Middle East, Southeast Asia, Tropical Africa, and Latin America are apt to remain power vacuums during this period, owing to their lack of unity, political instability, economic stagnation, and cultural heterogeneity.