It’s not easy being onstage if your last name is Chaplin, but despite the popular myth inspired by his dark hair, pale skin, and disconcertingly familiar presence, Ben Chaplin is no relation. He’s doing his non-grandfather proud nonetheless, heating up romantic comedies like The Truth About Cats and Dogs with his dream-guy nonchalance, and wowing them in the West End, with what The Independent called his “terrific restless intensity” as Tom in Sam Mendes’s recent production of The Glass Menagerie. Now he’s poised for his Broadway debut in The Retreat From Moscow. “The title is misleading,” he says. “But it’s a fairly simple metaphor for a marriage breaking down.” Chaplin plays the 32-year-old only child of a middle-class English family headed by John Lithgow and Eileen Atkins. “He’s caught in the middle. I find only children hard to relate to,” Chaplin says. “They become strangely siblinglike with their parents, and their retreat is time alone.” Happily for Chaplin, who moved to the city two years ago, and whose own parents were cheerfully married for 43 years, his own retreat is Slate, the local pool hall.