Bill Lynn's Long Halftime Walk, By Ben Fountain

Billy Lynn is 19, from a hick town in Texas and a member of Bravo company on leave from the war in Iraq. Bravo company are heroes of a frenzied firefight against insurgents and, wouldn't you know it, Fox News captured the whole bloody mess. It's now a YouTube sensation. So this isn't R&R: the boys are on a nationwide "victory tour", a shameless piece of boosterism after the non-appearance of WMDs.

Billy Lynn's Halftime Walk takes place on the day of Bravo's final meet-and-greet, at a football match in the Dallas Cowboys' stadium, before they're shipped back to the front line. They joke, they cuss, they brawl, they dream of hooking up with a cheerleader or, even better, the half-time entertainment, Destiny's Child. But before that unrealisable fantasy, they must be paraded one last time before the crowds who love them, who need them, who ask them what it was really like. Anything but acknowledge that they are killing machines.

Amid this outpouring of infantile emotion, Ben Fountain's brilliantly drawn Billy emerges as the lone sane voice: "Billy suspects his fellow Americans secretly know better, but something in the land is stuck on teenage drama, on extravagant theatrics of ravaged innocence and soothing mud wallows of self-justifying pity." He knows his life is worthless, and war is hell, but he "sees no great appeal in these tepid peacetime lives".

But Billy is not a vehicle for an exposition on the idiocy of US culture, but a real young man. He doubts, he rails, he lusts. (The scenes at home in which he's trying not to get turned on by his sister in a bikini are a gorgeous vignette of dysfunctional domestic life.) He wants real love and the telescoped romance with a cheerleader, Faison, is convincing and heartbreaking.

The book is lit up by verbal pyrotechnics, although there are times when you feel machine-gunned by half-formed metaphors, sandbagged by similes. And while Fountain's observations are generally sharp, a pronouncement such as "Somewhere along the way America became a giant mall with a country attached" is sophomoric and trite.

That aside, this is an exhilarating ride; funny, oddly touching, written with garish clarity. If Billy has a conclusion, it's that there are no answers. "Silence [is] truer to the experience than star-spangled spasm, the bittersweet sob, the redeeming hug, or whatever this fucking closure is that everybody's always talking about. They want it to be easy and it's just not going to be."

Billy Lynn's Halftime Walk is not the "Catch 22 of the Iraq War" as the book's jacket screams: there's no paradox – the characters are under no illusions about the sanity of the undertaking. It's about the American way of watching war, brought to you by General Motors. And in Billy we've found a hero for our times.