Still, the approach would risk catastrophe. Local leaders and police officers are more accountable to the people than soldiers are, and they know their needs better than Washington politicians do. Where extra help is needed, the National Guard, under the command of governors, is up to stopping riots. Deploying troops against the wishes of state and city leaders would only inflame passions, and could provoke a constitutional crisis.

Perhaps that’s why Secretary of Defense Mark Esper opposes the move. “The option to use active-duty forces in a law-enforcement role should only be used as a matter of last resort and only in the most urgent and dire of situations. We are not in one of those situations now,” he said yesterday in a press conference. “I do not support invoking the Insurrection Act.”

Those reasons alone are sufficient to reject the approach. Yet another concern should loom even larger: Trump has shown himself unfit to lead the sorts of operations under discussion.