It is easy to forget how popular Neville Chamberlain was in the autumn of 1938. Proclaiming ‘peace in our time’ after signing the Munich Agreement, he was heralded as the deal-maker supreme. A leader who’d averted needless bloodshed and whose critics were merely warmongering naysayers. You don’t need me to tell you the rest of the story, but you might have thought its lessons wouldn’t be so easily forgotten.