Who is the principal military advisor to the President, National Security Council, and SecDef?

The Chairman of the Joint Chiefs of Staff serves as the principal military advisor to the President, the National Security Council, and the Secretary of Defense. This role is crucial as the Chairman provides strategic direction, military advice, and guidance based on the input from all branches of the military, which is essential for informed decision-making in national security matters. The position carries significant authority and influence, as the Chairman is responsible for communicating and advocating the military's needs and views.

The other choices represent significant positions within the military and defense framework but do not hold the primary advisory role to the President and other key national security leaders. The Vice Chairman assists the Chairman and can step in if necessary, but the ultimate authority and responsibility lie with the Chairman. Directors of specific policy areas provide support and expertise, while the Chief of Staff of the Air Force focuses on Air Force-specific issues and does not advise at the highest levels of the national defense structure.