In 1973, Maj. Harold Hering started a process that would end with him being discharged from the Air Force by asking one simple question during training: “How can I know that an order I receive to launch my missiles came from a sane president?”
His point was that he felt that it would be a betrayal of his oath to launch nuclear weapons if the order came because the President was mentally unstable, or even just temporarily incapacitated. Would it be right to end the world just because the President’s a mean drunk who holds a nuclear football?
The Air Force was unable to give Hering an answer that satisfied him, going so far as to say that the President’s sanity was outside his need-to-know. The chain of command for launch orders doesn’t care about the President’s mental stability. It is only concerned with proving identity. If the order to nuke Moscow is proven to come from the President, you nuke Moscow.
Hering found this unacceptable and refused to agree with it. As a result, an Air Force panel recommended he be discharged.