EDITOR'S NOTE: This article appears in the May 3, 2004, issue of National Review. More than 30 years after he returned to voluntary, and happy, obscurity as a Houston lawyer, 58-year-old John O'Neill is making a prime-time comeback. Who's John O'Neill? He was the Vietnam veteran — a former commander of a Patrol Craft Fast, better known as the Swift boat — who famously debated one John Kerry, a fellow Swift skipper, for 90 minutes on The Dick Cavett Show back in 1971. C-SPAN excavated this particular television gem a couple of weeks ago and re-broadcast it. In 1971, Kerry...