With what Trump is doing now, provoking North Korea, risking actual destruction of part of the US, he is violating the system's rules on its own terms. He's committing an actual threat against US national security. And you would think that in just pragmatic political terms in Washington, that is the kind of thing that could be grounds for impeachment. But as long as he sits in that chair, it's true, the commanders are obligated to obey his order.
