To adapt Churchill: Never in the field of global diplomacy has so much been given away by so many for so little.

Britain and France's capitulation to Nazi Germany at Munich has long been a byword for ignominy, moral and diplomatic. Yet neither Neville Chamberlain nor Édouard Daladier had the public support or military wherewithal to stand up to Hitler in September 1938. Britain had just 384,000 men in its regular army; the first Spitfire aircraft only entered RAF service that summer. "Peace for our time" it was not,...