It's called MORAL LAW. I was quoting from the Pope, as posted by fl_engineer. Every state has such a law, btw, incorporated into its constitution. The military also has such, so that those who are "commanded" to commit that which is wrong cannot be forced to commit such a wrong. No government authority can force me to commit a criminal act, regardless of what lesser laws are in place.
An army of one. That should do it.