A faked video of Donald Trump points to a worrying future

“DEAR people of Belgium. This is a huge deal. As you know, I had the balls to withdraw from the Paris climate agreement, and so should you.” It sounds like Donald Trump—a bit, anyway. It is definitely a picture of Donald Trump. But the person in the video, produced by sp.a, a left-wing Belgian political party, is not quite the American president. It is a computer-tweaked facsimile, into whose mouth has been put a not-entirely serious homily about Belgium’s carbon emissions.Faked images are not new. Stalin airbrushed his enemies out of history by having them removed from official photographs. Visual-effects studios in Hollywood transpose actors’ faces onto the bodies of fitter, more disposable stunt doubles. But tinkering with video is hard. Doing it well requires specialists who are scarce and expensive.