The terrorist attack at a Moscow concert hall exposed Russian President Vladimir Putin's image as the "great protector" of his country and showed how he is "losing control," according to a British journalist and author who has written about the dictatorship of Nazi Germany. Roger Boyes, who has written books about how Adolf Hitler rose to and maintained power, started an op-ed in The Times of London by asking if dictators keep their citizens safer than democracies do. Co-author of Surviving Hitler: Corruption and Compromise in the Third Reich and Seduced by Hitler, Boyes was the newspaper's Eastern Europe correspondent...