I can think of exceptions to each of the 10 oaths depending upon just how bad things are in the instance. Probably, so can anyone.
But the point remains, in my opinion. Yes, part of your oath is to obey lawful orders of the president, and your commanders. And any soldier who makes the decision to refuse what he considers to be an unlawful order is asking for serious trouble; its not something anyone would do lightly nor should they.
But the higher oath taken is to the constitution.
And there is a higher demand still upon a man, which is to God and to conscience. Every soldier must one day take off his uniform, and he must never do anything he can’t live with when that day comes. If ordered to move against American citizens he has to consider the morality of his actions, and the constitutionality of what he is being ordered to do.
There are clearly going to be cases where he might legitimately be called upon to establish order in the face of an insurrection. If the insurrectionists are trying to overthrow the constitutional order, then his duty is clear. If the insurrectionists are rebelling against an unconstitutional order, then he has some soul-searching to do. And in that case the lawfulness and the morality of his orders, and the legitimacy of the powers issuing those orders needs to be considered.
There will be gray areas and everyone’s tipping point will not be the same. But the constitution, and your own sense of honor have to come first in such a situation. You may have to resign, you may have to face arrest in order to stay on the right side of things. If things don’t turn around, preachers and common citizens may soon face the same dilemma. Keep your head down and hope for better days, or stand up and face lawsuits and official harrassment.
Reading this made me think of the possibility that a lawful order may be given and yet, it would require one to disobey that order. What if a conscentious objecter is caught in a combat situation and is ordered to help defend a position? What if a corpsman is ordered to withold medicine that might be used to save others?
The point is, as you stated, that there is a higher oath to God and moral values.