Seventy years ago, Britain and France, partners in decline, tried to take the Suez Canal by force. Britain could always console itself that it was handing over to a democratic, anglophone and mostly white superpower. In contrast, the US has lost ground to China, with which it shares none of those characteristics. Even under a normal president, the US might be behaving badly around about now. Status-anxious countries have to puff themselves up. It is a rare superpower that takes decline well. Those of us who live a better life than we were born into cannot begin to understand the trauma of going in the opposite direction. A small drop in status can unhinge people, even if their absolute position remains good. It was the Weimar middle class, inflated out of their savings during the slump, who turned to the National Socialists in elections, not necessarily the worst-off. The individual matters, no doubt. In fact, Trump has won me over to the Great Man theory of hist...