10. US. Military Chain of Command:

The President of the United States

...to...

The Secretary of Defense

...to...

The Unified Combatant Commanders

Note that while they may be included into the communications (not command) chain by a specific executive order, the Joint Chiefs of Staff (JCS) are not in the chain of command. This means that while the President or Secretary of Defense can choose to pass messages to the Unified Commanders through the Chairman of the JCS, the JCS does not have authority to command those units except through the direction of the President and/or the Secretary of Defense.

Together with their designated alternates, the President and Secretary of Defense are collectively referred to as the National Command Authorities. Some actions, especially some of those relating to Defense Conditions and nuclear weapons release, require commands from the NCA; no subordinate may generate them.