Since the United States Army acquired its first Wright flyer and integrated the airplane into battle, the role of airpower has been a constant source of friction between ground and air forces. Army and Air Force cultures, doctrines, shared experiences, and fratricide involving close air support (CAS) have all helped shape the tenuous relationship between the two Services. Since the end of the 1991 Gulf War, there have been 13 CAS fratricide events, killing or injuring 197 people. In all but one instance, training was a causal factor. Yet, there is no formal requirement for joint CAS training. In the early 1980's with the establishment of the U.S. Army ground combat training centers and the corresponding U.S. Air Force Air Warrior training programs, the Services began habitual close air support training. However, with the shift from medium intensity conflict to counter-insurgency and stability operations, pre-deployment CAS training at the CTC's has nearly ceased. While there has not been an increase in fratricide corresponding to this decrease in training, the integration of CAS has decreased and the potential for a fratricide event has increased. The Army and the Air Force must increase their focus on improving joint CAS training as the lives of U.S. soldiers may well depend upon the effectiveness of CAS to hit the correct targets while supporting their operations.Since the introduction of the airplane into military operations, airpower has played an important role in the conduct of war, both in its ability to attack in depth and in its support of friendly ground forces. The initial growth of airpower as a weapon of war was in direct support of ground forces during World War I. Shortly thereafter, early air power theorists such as Giulio Douhet and Billy Mitchell changed the emphasis away from support to ground troops, envisioning vast air armadas that could avoid stalemates on the ground and strike an enemy's political and military centers with strategic bombardment. While ground and air forces have worked together in all major conflicts since World War I, the US Army and US Air Force have continuously disagreed on how airpower best supports ground forces.Prior to the Second World War, most Army generals believed the best use of airpower was to support ground troops by adjusting field artillery, conducting reconnaissance, providing real time intelligence, and providing close combat support. Airpower enthusiasts believed that after achieving air superiority, air forces should concentrate their efforts and use strategic bombing to attack the enemy's centers of gravity; thereby, destroying their ability and desire to wage war. Current US close air support doctrine can trace its foundations to North Africa during World War II.Years of neglect and intra-service rivalry left US forces unprepared for integrated air-ground operations in the deserts of North Africa. Initial integration efforts were disorderly and were most successful at increasing tensions between ground and air commanders.