Force planners must try to anticipate the future. This paper attempts to lay out a few simple visions of alternative futures and comment on how these alternatives might affect the Air Force and other armed services. Visions of the future may be partitioned into (a) the world environment the United States will find itself in and (b) the role America plays in that world. In the simplest breakdown, the future world security environment may be one of the following: "baseline," whereby all First-World nations prosper, Second-World countries progress, and Third-World nations struggle; "Getting better," whereby many countries benefit from improving economic and political climates, advancing technology, and international trade; or "Getting worse," whereby all countries struggle under the weight of poverty, population, pollution, and resource depletion. Within any of these world environments, the United States could continue in the role of leader, share co-equal status with other first-tier countries, or decline to second-tier status. This paper discusses every combination of world environment and U.S. role in terms of U.S. force requirements.