Christopher Nolan’s epic movie about the rescue of the British army from the beaches of northeastern France in May 1940 has become a worldwide box office success. This is splendid news for its makers, and can do no harm to American, Taiwanese, or for that matter Rajput audiences. In the eyes of some of us, however, its impact upon the British people is calamitous at this moment in our fortunes. Dunkirk contains no foreigners except a few understandably grumpy French soldiers. It is a British tale that feeds the myth that has brought Churchill’s nation to the cliff edge of departure from the European Union: there is splendor in being alone.