IT WAS LIKE a scene from the cold war. Kim Jong Un, North Korea’s leader, stepped off his luxurious bulletproof train this week having crossed into Russia’s Far East, to be greeted by a military brass band and whisked off to meet Vladimir Putin. Over a meal of duck salad and crab dumplings, washed down with Russian wines, the two dictators toasted what Mr Kim called the “sacred fight" against Western imperialism. Both men are throwbacks. Mr Kim is the grandson of a tyrant imposed on North Korea by Stalin. Mr Putin waxes nostalgic about Russia’s imperial past. Yet the...