Traces the usage of and meaning given to the terms "roles and missions" relating to the armed forces and particularly to the United States Air Force, from the birth of military aviation in 1907 to the end of the twentieth century. In particular, author Warren A. Trest explores the origins of the battles over post-World War II roles and missions between the Air Force, Army and the Navy, particularly in reference to "forward presence". Trest also explains the Air Force's unique institutional development, as use of air bombardment and surveillance grew in sophistication and importance, reinforcing the need for treating air power as a separate service. Included is a review of mission and role identification and separation attempts by Congress and various commissions.—Print ed.