his personal allegiance was to his unit and his country. his mission was allied with the UN and they did whatever it was the UN had them there for as that was the mission.

Edit: more to the point I think you are getting at, he would defy unconstitutional orders and risk UCMJ if he had to. Because his first allegiance is our country and his unit. He also had a whole cache of personal weapons he would never surrender. Those things would get buried in a vault somewhere before the govt would take them from him.