A good question

Q: How can any missile crewman know that an order to twist his launch key in its slot and send a thermonuclear missile rocketing out of its silo—a nuke capable of killing millions of civilians—is lawful, legitimate, and comes from a sane president?

A: "Shut up!" they explained.

The fact that we are still here this long after 1945 is due entirely to the grace of God and the strenuous efforts of our guardian angels.