I ___, do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all ... discharge the duties of the office on which I am about to enter.

and that I will obey the orders of the President of the United States and the orders of the officers appointed over me, according to regulations and the Uniform Code of Military Justice.

or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States ...