At the start of the Summer Olympics last month, the eyes of the world were upon London, and millions caught their first glimpse of the unruly blond thatch that is the trademark of Boris Johnson, the city’s recently reelected mayor. A portly, rumpled presence, he stood in sharp contrast to the…

Long before their tanks roared through the Ardennes, the Nazi regime had Paris in its sights. Hitler’s lunatic ambition had its crafty side; as his urbane diplomats charmed French aristocrats, his secret minions mounted a cultural offensive aimed at softening the French will to resist. Deep in the…