U.S. Department of Defense

The United States Department of Defense is the federal department charged with coordinating and supervising all agencies and functions of the government relating directly to national security and the military. The Department of Defense is the major tenant of The Pentagon building near Washington, D.C., and has three major components, the Department of the Army, the Department of the Navy, and the Department of the Air Force. Among the many agencies are the Missile Defense Agency, the Defense Advanced Research Projects Agency, the Pentagon Force Protection Agency, the Defense Intelligence Agency, the National Geospatial-Intelligence Agency, and the National Security Agency. The department also operates several joint service schools, including the National War College.