Final answer:
The first drafts of joint and Armed Services doctrine were circulated around the Department of Defense following the establishment of the Department of Defense in 1949, as a result of the National Security Act of 1947 and its 1949 amendment. These reforms were essential for creating a unified military structure capable of Cold War defense and offense.
Step-by-step explanation:
The Joint Staff and Armed Services began circulating the first drafts of joint and Armed Services doctrine around the Department of Defense post the legislative changes that led to its formation. This process followed the passing of the National Security Act of 1947 and the amendment in 1949, which together restructured the U.S. military and established the Department of Defense by combining the Department of War, Department of the Army, Department of the Navy, and the newly created Department of the Air Force into a single unified department.
The intent behind these reforms was to ensure a capable military offense and defense during the Cold War era, highlighting the need for cooperation and coordinated doctrine among the various branches of the Armed Services. The resulting joint collaborative efforts established the foundations for current military doctrine, procedures, and the establishment of the Joint Chiefs of Staff.