What authority do Secretaries of the Military Departments hold?

The authority held by Secretaries of the Military Departments includes exercising authority over the Chiefs of Services not assigned to combatant commands. This means that they play a crucial role in overseeing their respective branches of the military—Army, Navy, and Air Force—when those branches are not operationally assigned to specific geographic or functional combatant commands.

The Secretaries are responsible for administrative, budgeting, and policy decisions, as well as ensuring that the military services meet the needs of the combatant commanders. However, once forces are assigned to a combatant command, the command authority shifts to the respective combatant commander, illustrating a distinct separation of administrative and operational authority.

Understanding this hierarchy is essential for recognizing the balance of power and responsibilities within U.S. military leadership, which facilitates effective administration and strategic operations across different military contexts.