The twentieth century witnessed the emergence of three-dimensionality in war: surface forces flow became prey for attackers operating above and below the earth and its oceans. The aerial weapon, prophesied for centuries, became a reality, as did air power projection forces. This insightful book by Warren A. Trest traces the doctrinal underpinnings of the modern United States Air Force, the world's only global air force. We the men and women who serve in the Air Force, but also our fellow airmen in America's other military services are the heirs and beneficiaries of a long heritage of doctrinal development and military thought. Our predecessors pursued a vision of airborne global reach and power that often put them at odds with those who could not break free of the confines of conventional thought and lock-step traditionalism. Fortunately, they had the courage of their convictions and the faith in their vision to continue to pursue the goal of global air power despite such resistance. Today, America is a genuine aerospace power, and that pioneering vision dating to the days of the Wright brothers, has expanded to encompass operations in space and between the mediums of air and space. As we approach the new millennium, it is well to ponder the lessons and the history of how a small group of truly gifted airmen transformed their nation's military establishment, and, in so doing, the world around them.