This National Defense University Military History examines the role of the U. S. Marine Corps in the defense unification controversy of 1944-1947. World War II demanded the coordinated training, equipping, transporting, and employing of huge forces and soon exposed the organizational flaws of the prewar military establishment. Sentiment for unifying the U. S. military effort predated World War II, but the war provided the impetus for a major reorganization. Long before the end of the war, there was a growing conviction in the War Department and Congress to establish a system to coordinate and unify the activities of the U. S. Armed Forces. The National Security Act established a more unified defense entity in 1947, but the Marine Corps - deftly practicing the "politics of survival" - emerged with its organizational identity and integrity essentially intact. The author, Colonel Gordon Keiser, USMC, relates the history of how the Corps managed to survive amidst the political maneuvering of more than an account of one Service's struggle to endure. It contains interesting insights into the origins of the modern Department of Defense and the current defense policymaking process. Although today's circumstances are vastly changed, the Nation remains concerned about issues such as defense organization, the proper role of military lobbying, and the relationship of the Services to one another and to the Congress.