'Did the order come from a sane president?': Warning by Nixon-era nuclear munitions expert reemerges in Trump's threat
President Donald Trump and a mushroom cloud (composite image)

"How can I know that an order I receive to launch my missiles came from a sane president?”

The question was asked in 1973 by Harold Hering, an Air Force major studying to be a missileer, or one of the people who turns the keys that unlock the deadliest of missiles.

The question, raised again by the Washington Post on Wednesday, remains as prescient now in light of President Donald Trump's "fire and fury" threat against North Korea as it did then -- when Hering rightfully questioned whether or not President Richard Nixon was, at the height of the Watergate scandal, of sane mind. The question ultimately caused the fledgling missileer to be fired.

At the time, concerns about Nixon's mental health were so severe, his Defense secretary James Schlesinger asked to be alerted if the president began giving any "unusual orders."

"I could leave this room and in 25 minutes 70 million people would be dead," Nixon reportedly once bragged in a meeting.

Hering, a man of far less prestige but in a potential position of immense import, wanted to know if a system of checks and balances existed on the president's access to weapons of mass destruction -- a "forbidden question" whose answer is so dangerous, it cost him his job.

In April, months before Trump made his 'fire' and brimstone comments, WNYC's Radiolab interviewed Hering about the question that got him fired. He discussed neither Trump nor North Korea by name, but his answers remain important. Listen to the interview below, via Radiolab.