National Command Authority

National Command Authority (NCA) is a term used by the Department of Defense of the United States of America to refer to the ultimate lawful source of military orders. The NCA comprises the President of the United States (as commander-in-chief) and the Secretary of Defense (as the deputy to the commander-in-chief) jointly, or their duly deputized successors, i.e. the Vice President and the Deputy Secretary of Defense. The term also refers to communications with the commanding officers of the Unified Combatant Commands to put U.S. forces into action.