All military orders come down under the authority of the Commander in Chief, through the chain of command.
Part of basic training is to memorize and be able to state, the chain of command. If there are changes, the changes have to also be memorized.
Bingo. And it's Captain Rhodes who has to follow orders. Major Ausprug is the Army attorney
Technically all military orders come from the Commander in Chief..
The President is Commander in Chief of the Army. That much is explicitly in the Constitution. The theory is that all authority then flows down from him to the individual service members. Thus if he is illegitimate, lower level orders implementing his high level ones (stay in Afghanistan.. for now, for example) are also illegitimate and could subject military members to legal ramifications at a later date. ("Just following orders" hasn't been a defense in a good while)
Maj. Ausprug is the Army's attorney. The plaintiff in this case is Captain Rhodes. She is the one putting herself at risk. But only if she actually violates the diploment order. Technically she is asking for clarification of the legitimacy of the order, before violating or obeying it. Without knowing if the order is legitimate, she maintains she is taking a risk either way.