At what point should the military refuse the orders of civilian leadership? A tactical level order to shoot civilians (or similar, non-cliche situation) should

At what point should the military refuse the orders of civilian leadership? A tactical level order to shoot civilians (or similar, non-cliche situation) should be disobeyed. However, is it the military's responsible to disobey the decisions of a duly elected civilian government, such as the Iraq War resolution[0]? Civilian control of the military exists for a reason, and allowing/requiring the military to go against it would have wide ranging consequences. There are definitely unique cases to be explored, but credit/blame need to be assigned to the party responsible for the decision. [0]: https://en.wikipedia.org/wiki/Iraq_Resolution https://en.wikipedia.org/wiki/Iraq_Resolution