This was an Oscars night with a British accent: so many Brits (and a supremely talented Irishman) strode up to the mic with their statuette, often baffling their Hollywood audience by talking about Mother’s Day (the Americans think that happens on 12 May). So it was fitting that the best picture was created by an Englishman, director Christopher Nolan. Oppenheimer is the film whose awards-journey crescendo has happened to coincide with Vladimir Putin threatening to use nuclear weapons if Nato personnel are deployed in Ukraine – while releasing on Russian state TV-taped evidence that British intelligence officers were deployed in...