‘A failure of British statecraft on a scale unseen since the Suez crisis.” You might think the former transport minister Jo Johnson’s parting shot at Theresa May stood a fair chance of attaining immortality in the A-level history exams of the future.

Martin Wolf, of the Financial Times, attempted the question. “Comparisons with the 1956 Suez crisis do not get close to the mark,” he opined last week. “This is a far more significant mess than that.”

But what could be worse than Britain’s humiliating withdrawal from the Suez Canal zone in 1956? The answer, according to David Keys, of The Independent, is the Munich agreement of 1938.

Exchanging the acrid, smoke-filled air of northern California for the damp, foggy miasma of London was something