This monograph analyzes US military air power - US Army relations form 1907 to the present. It emphasizes one aspect of those relations-how air forces intended for the tactical support of ground forces can best be controlled and integrated into the overall ground battle. After a review of changing air- ground relationships from 1907 to 1982, this work examines the 31 Initiatives, the most recent US Army - US Air Force agreement on developing joint combat forces and battlefield cooperation. It also discusses the process behind the formulation of the 31 Initiatives and discusses how that process provides one example of the introduction of innovation or change into a military organization. In addition, this work details the immediate and longer term response of the two services to the Initiatives. The importance of this monograph is twofold. It supplies a case study of innovation and, more significantly, it places the 31 Initiatives in their place as the far-reaching and comprehensive end product of a decade of Air Force - Army cooperation.