The Secretary of Defense is the 'Principal Assistant to the President in all matters relating to the Department of Defense', and is vested with statutory authority ( 10 U.S.C. Armed Forces and Chief Executive of the Federal Government. The President of the United States is, according to the Constitution, the Commander-in-Chief of the U.S. The Department is protected by the Pentagon Force Protection Agency, which ensures law enforcement and security for the Pentagon and various other jurisdictions throughout the National Capital Region (NCR). The Pentagon Reservation in Arlington County, Virginia, across the Potomac River from Washington, D.C., is the Department's headquarters. During times of declared war (or by Congressional direction), the Coast Guard operates as a part of the Navy this has not happened since World War II, but members have served in undeclared wars and conflicts since then while the service remained in its peacetime department. Code, the Coast Guard is at all times considered one of the six armed services of the United States. Prior to the creation of DHS, the Coast Guard was under the control of the Department of Transportation, and earlier under the Department of the Treasury. In wartime, the Department has authority over the Coast Guard, which is under the control of the Department of Homeland Security (DHS) in peacetime. Each is led by a service secretary, who is below Cabinet rank. Ĭivilian control over matters other than operations is exercised through the three service departments, the Department of the Army, the Department of the Navy (which includes the Marine Corps), and the Department of the Air Force (which includes the Space Force). Including those items brings the total to $560.6 billion for 2015. This figure is the base amount and does not include the $64.3 billion spent on 'War/Non-War Supplementals'.

The DoD's annual budget was roughly US$496.1 billion in 2015. elements of multinational commands (such as NATO and NORAD), as well as non-combat agencies such as the Defense Intelligence Agency and the National Security Agency. It includes the Army, Navy, the Marine Corps, Air Force, Space Force, the Unified combatant commands, U.S. The United States Department of Defense (DoD) has a complex organizational structure. The Pentagon, headquarters of the United States Department of Defense.

Is the president the commander in chief