SILVER SPRING, MARYLAND—Staff Sergeant Christopher Bain unwittingly pulled his luxury Chrysler into the red zone of the Metro station here, stopped, and then watched as a stocky, Kevlar-wrapped policeman made a slow, expressionless approach. "This zone is for buses only," said the cop, from somewhere beneath a dark baseball hat pulled low. He gestured to an invisible sign 100 yards away near the main road. "Your license and registration please." The policeman might not have noticed the eight-inch scar that looks like a shark bite on Bain's left arm, an injury he sustained during a mortar attack on his base...
