The formal decisions, documents, and events that established the roles, missions, and functions (RMF) of the U.S. Department of Defense (DoD) and the military services in the early postwar years are over 70 years old. Although the foundational documents and agreements have been modified, the original division of labor among the services remains largely unchanged, and a fundamental reassessment of RMF may be in order. At least two services-the U.S. Air Force (USAF) and the U.S. Army-envision themselves as the principal integrator of All-Domain Operations. Additionally, the creation of the U.S. Space Force (USSF) raises RMF issues both within the Department of the Air Force (DAF) and across the services. In this report, the authors identify RMF disputes that have endured as problems for the USAF, some factors associated with major RMF events, and reasons why reform efforts have often failed. The authors have crafted a framework for analyzing the RMF implications of strategic-level guidance, such as the 2018 National Defense Strategy, emerging operational concepts, and the creation of the USSF. The key question for USAF leaders is whether the existing framework is fundamentally sound (requiring only modest adjustments), whether it should be replaced by another agreement that would recast RMF assignments, or whether narrowly defined responsibilities are a hindrance to agility and innovation and should be scrapped entirely. The authors present their findings and recommendations, considering how the vision that USAF leaders choose for the service's future will influence the relative attractiveness of possible courses of action.