When Russian President Vladimir Putin warned earlier this month that Western approval for Ukraine to strike deep inside Russia would mean Moscow was at war with NATO, Russian propagandists rushed to rattle the nuclear saber. Alexander Mikhailov, director of the Bureau of Military Political Analysis, called for bombing plywood mock-ups of London and Washington — complete with reproductions of Buckingham Palace, Big Ben and the White House — to simulate nuclear strikes, so that they would “burn so beautifully that it will horrify the world.” The speaker of the lower house, Vyacheslav Volodin, warned that strikes on Russia would lead...