The sniping started immediately. Anthony Swofford was promoting his book, Jarhead, at a reading in Portland, Oregon. We were days away from Bush's declaration of Gulf War II, and Swofford's audience was, as all Americans were, anxious. A sad-eyed Vietnam Marine veteran complimented Swofford for capturing the horror and futility of war. He was rudely interrupted by a brash young Marine, buzz-cut and packed for Kuwait, who ordered the vet quiet, then told Swofford that the book had inspired him for the job ahead. The vet wheeled around and said, "You're a fool, boy," and the young Marine began to chant "Semper fi."

Both men had read Swofford's book, and both had interpreted it differently. In reality, Jarhead is a calm, almost dispassionate at times, piece of war reportage serving as a memoir (the book actually began life as a novel, until the author found himself naming one of the characters "Swofford"). It's Swofford's story of being caught up in the first Gulf War, but his keen (some might say cold) objectivity renders the author into an Everyman figure, which is one of the book's strengths. The reader can easily slip into his boots and feel the punishing Arabian heat and deathly boring wait for action. One smells the burning oil fields and observes fellow grunts desecrating Iraqi soldiers' corpses, as if on a Joe Friday fact-finding hunt. One reader sees waste through Swofford's eyes, while another finds adventure.

The problem with Sam Mendes' film version of Jarhead is how to dramatize Swofford's incisive, I Am a Camera detachment. Unfortunately, Mendes falls back on appropriations from a raft of classic war (and antiwar) films that he's studied. So, the film flits impossibly back and forth between wanting to be Malick's The Thin Red Line or Altman's M*A*S*H. There's also more than one nod to Coppola's Apocalypse, Now — a film, ironically enough, that the Marines in Jarhead use to "psyche" themselves up for battle, and interact with at the same intensity level as suburban Goth teens at a midnight screening of Rocky Horror.

In losing the tone of Swofford's book, the film loses momentum. All the set pieces are spectacularly filmed (especially the hellish oil field fires and the grisly Highway of Death, probably America's greatest war crime). Mendes is also good at capturing the degrading and often inhuman treatment of grunts at the hands of their superiors (Abu Ghraib is best understood as an elaboration upon daily boot camp torture). But when a colonel shows up at a bombing site with a lawn chair, we search the background for the smirking face of Catch-22's Yossarian. Or when Jamie Foxx's Sergeant Sykes looks out on a sea of burning oil rigs and says proudly, "Who else gets to see this shit?" we hear Robert Duvall's aptly named Colonel Kilgore in Apocalypse, Now: "I love the smell of napalm in the morning."

The performances are all fine, if uncertain of motivation. Jake Gyllenhaal does as much as he can with the thinly drawn characterization of Swofford, though he's easily bested by Peter Sarsgaard's Troy, a toughened soldier with hair-trigger emotions. Sarsgaard is particularly good in a scene where Troy breaks down when he isn't able, at last, to participate in the war as a sniper.

Sniping critics have complained of the film's lack of action, as if they were being denied The Green Berets, Part II. But Swofford's war was like distant weather: Something happening beyond the horizon or dunes. Jarhead is about the merciless banality of war interspersed with flashes of gut-tearing terror.