He counts his unit's kills meticulously, each one a tick in black pen on his khaki helmet which is, by now, bleached by the sun and battered from battle. Perched in the turret of his tank, just behind the barrel that is hand-painted with intimidating war cries such as "kill 'em all" or "I'm a motherf***ing warrior", he talks only to those Iraqis with the temerity to approach: he feels vulnerable without a 60-ton Abrams girding his loins. It is impossible to read anything in his eyes because they are always obscured by mirrored sunglasses. Only in the safety of...