In Mexico City last week Diego Rivera, longtime Communist sympathizer, was brushing in the finishing strokes on a new mural. Its title: The Nightmare of War and the Dream of Peace. Rivera called it "the best thing I have ever done"; it was, at any rate, one of the most violent.
In the center panel, the mushroom cloud of an atomic-bomb explosion rose over scenes of destruction, flint-faced firing squads in U.S. uniforms, crucified and gibbeted North Koreans. At the left stood a benign Stalin, filially flanked by a boyish Mao Tse-tung, who held out the Red dove of peace to three...