The Department of Defense consists of the army, navy, air force and marines as well as air combat agencies such as the National Security Agency and the Defense Intelligence Agency. The department’s annual budget was approximately $ 786 billion in 2007. This does not include the tens of billions of extra dollars that the US Congress has devoted to the department throughout the year, particularly the Iraq War. It also does not include the United States Department of Energy spending on the design and testing of nuclear weapons.
The civilian side controls the department in matters rather than operations and is carried out through three ministries under the United States Department of the Army, the US Navy (which includes the United States Marine Corps) and United States Air Force. Each ministry has its own minister below the cabinet level.