No one knows how to torture a television executive quite like David Letterman. At NBC his bosses were "pinheads"; at CBS he has saluted his current boss, network president Les Moonves, with embarrassing footage from Moonves' days as an actor. But Letterman's most recent bit of mischief--threatening to leave CBS, his late-night home of the past eight years, for rival ABC--deserves a lifetime-achievement award: He has managed to make executives at both networks miserable.
Letterman's latest contract talks with CBS have been so fractious that, according to a source involved with the talks, the normally smooth and polished Moonves at...