The Department of Defense is made up of three Military Departments:the Department of the Army (United States Army),the Department of the Navy (United States Navy and Marine Corps),and the Department of the Air Force (United States Air Force and Space Force) along with the National Security Agency (NSA),and the Defense Intelligence Agency (DIA). The Department of the Navy includes the Navy and the Marine Corps. Also, during times of war the United States Coast Guard is under the authority of the Department of Defense.