The study examines how designing a force for the most-dangerous scenario affects the Air Force's ability to cooperate with the Army and conduct joint missions, specifically CAS. Tomorrow's fight is unknown, but a near certainty is that it will be a joint fight and therefore it is imperative for the Air Force to foster inter-service cooperation. The path this paper treads is to understand how the Air Force derives its most-dangerous scenario and the implications or the effect on the joint team. The complete analysis revolved around a theoretical framework. The theory proposes that the services are motivated more by fear than potential gain, and they are particularly motivated by their greatest fears, expressed as the "most-dangerous scenario." When a perceived crisis occurs, it reinforces the threat of the scenario and the Service's unique role in it, thereby entrenching the Service in patterns of behavior designed to protect the scenario and its role. When their greatest fears do not overlap, the Air Force and Army diverge from cooperative behavior, even to the point of neglecting joint missions, specifically CAS. The framework incorporated two organizational theories. They are Lina Svedin's Organizational Cooperation in Crisis and Dominic Johnson and Dominic Tierney's Rubicon Theory of War. The framework offers scaffolding necessary to hang the three historical case studies: Korea, Vietnam, and Desert Storm. The case studies focus on the three interwar year periods from 1945-1991. The interwar years were selected for two reasons. Today, as the drawdown from Afghanistan is completed, the US military is approaching an interwar period. The lessons from previous interwar periods may be applied early enough to forestall negative outcomes. Secondly, in times of war, political objectives and end states act as forcing functions that drive cooperation. This unified effort can be difficult to stimulate in peacetime void of common aims and the moral imperatives of combat.This study concludes that an assessment of the strategic landscape and recognition of the moderating elements of war, political and public entities, must influence the design of the most dangerous-scenario. When the Services perceive a different strategic landscape and craft divergent views of future conflict, there is a desire to diverge from cooperation and engage in conflict with one another, tearing at the seams of trust. Willful and deliberate cooperation is all based on trust. Trust is the sinew that holds joint relationships together; without it the pressures of significant crises and even war can bend or break those relationships. The interwar years matter, not only to build and reconstitute the hardware necessary to fight, but to solidify the relationships vital to preserving American lives and national treasure when it comes time to fight.