Current funding for the Gi21 program ended on September 30, 2008 and the information found in the program modules is up-to-date as of December 31, 2008. To facilitate use of the modules from now till the future continuation of the program, new documents can be posted from each module and sub-module main pages and the community discussions are open. However the main module pages and documents will not be updated. If you have any questions, please contact Kirsten Clark.
The Department of Defense is responsible for providing the military forces needed to deter war and protect the security of our country. The major elements of these forces are the Army, Navy, Marine Corps, and Air Force, consisting of about 1.3 million men and women on active duty. They are backed, in case of emergency, by the 825,000 members of the Reserve and National Guard. In addition, there are about 700,000 civilian employees in the Defense Department.
Under the President, who is also Commander in Chief, the Secretary of Defense exercises authority, direction, and control over the Department, which includes the separately organized military departments of Army, Navy, and Air Force, the Joint Chiefs of Staff providing military advice, the combatant commands, and defense agencies and field activities established for specific purposes.
(from US Government Manual, http://www.gpoaccess.gov/gmanual/index.html)