There was Superman in red leather boots, Ronald McDonald clutching a bottle of beer, and Santa Claus about to look through a pair of binoculars. A benign if motley bunch, you may think. But they were enough to provoke an international diplomatic rebuke, it emerged on Wednesday, after they featured in an impudent make-over of a Soviet war memorial. Members of Russia's government were said to be seething. An unidentified street artist struck last weekend, daubing paint on a high-relief statue in Sofia, Bulgaria, to transform the monument's Red Army soldiers into a tableau of storybook characters. The artist's...