Doctrine describes and prescribes how we intend to develop, organize, train and employ our military force to accomplish objectives. This paper proposes that air and space power is misunderstood by civilian and military leaders because our shared understanding of the nature of warfare and the purposes of military power is essentially unchanged from Napoleonic concepts of warfare. In turn, air and space power doctrine-an expression of how the mediums can be used to achieve military objectives-is stuck in this outdated paradigm. Through the use of an analytic framework for doctrine that contrasts its characteristics with underlying assumptions, a sequence of flaws in fundamental (basic) and environmental (medium-based) doctrine is revealed and examined. Relying on a wide range of critics and practitioners as source material, the author highlights not only the common threads of argument, but also some shared conceptions of how the flaws might be corrected. Two steps are recommended to secure the foundation: first, recognize the change in the nature of war; and second, develop an air and space doctrine which links the flexibility of their power to the military purposes inherent in modern warfare. Military forces provide a nation’s ability to compel, coerce and deter adversaries, and reassure and sustain allies. This new foundation reveals the remarkable breadth of application for air and space power, and is shown to have a strong relationship to joint doctrine, the national security strategy, and joint and Air Force strategic visions.