"It's like a bad soap opera."

Watching the Dear John trailer, with different Nicholas Sparks fans at different times, I heard the same warning when his name flashed on the screen: "You know something bad will happen." Sparks, whose book the film is based on, is known for epic, bittersweet romances like The Notebook and Nights in Rodanthe.

The first half hour or so of Dear John, directed by Chocolat's Lasse Hallstrom is as lovely and intoxicating as the trailer. It's set against…