This study examines the nature and degree of the convergence of Army and Air Force airpower thinking and doctrine since the Vietnam War. The value of this effort lies in providing a better understanding of those areas of agreement which could form the conceptual basis for a comprehensive, conventional, land based airpower theory. Following the Vietnam War Air Force airpower thinking and doctrine splintered into "strategic" and "tactical" camps, while within the Army airpower thinking and doctrine remained closely tied to tactical land warfare doctrine. As the Army's basic doctrine evolved from a linear, firepower intensive "Active Defense" into the maneuver oriented "AirLand Battle", debate over centralized control of airpower led to a shift in both Army and Air Force airpower thinking from tactical-level CAS to interdiction and by 1986, to a joint, theater-wide, operational campaign perspective. Simultaneously, advancing sensor, computer processing and weapons guidance technology, combined with a renewed interest in the study of aerial warfare to cause reassessment and eventual recognition within the Air Force that "tactical" and "strategic" airpower concepts were artificial and limiting. By 1990, the dissolution of the Soviet Union and increasing non-linearity of the modern battlefield made airpower's mobility, firepower and flexibility increasingly important to both services. This paper finds that Army and Air Force airpower theory and doctrine have converged at the operational level of warfare. The kernel of a future airpower theory may be found in two propositions. The first is the general agreement between the Army and the Air Force that airpower can provide important, potentially decisive capabilities throughout a theater of operations when centrally controlled. The second proposition is found in the realization by the Air Force that distinctions between "strategic" and "tactical" airpower are artificial and limiting. The corollary to the second proposition is that the relative effectiveness of a particular airpower role or mission is situationally dependent.