The Officer’s Oath plainly mentions the orders of the President of the United States. An officer has the duty to not follow any orders he believes are unlawful, e.g., from an unlawful source.
“I, _____, do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; 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. So help me God.”
“I, _____, do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; 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. So help me God.”
Hey Greenhorne, the above is the Oath of Enlistment not the Commissioned Officers’ Oath. You don’t know what you’re talking about.
Google: “US Military Officers’ Commissioning Oath.”