The question has been gnawing away at the back of the mind since about 3am on 9 November, when the outcome of the US election become plain. The hysteria emanating from the Korean Peninsula drives it to the front of the mind. What happens if Donald Trump calls for the codes?
No president ever has. There were no codes in 1945. Harry Truman simply gave an order, and atomic bombs were dropped on two Japanese cities.
No president since has called for the codes – because of what Truman did. The neo-biblical devastation witnessed in Hiroshima and Nagasaki ensured the first-strike use of nuclear weapons was something no sane president would contemplate.
With a President whose sanity is in doubt, we face a danger no one saw coming. Nothing in the US Constitution, or beyond, is designed for a Commander-in-Chief with the capacity to take catastrophically impetuous decisions with incalculably cataclysmic consequences.