His observations draw a complex portrait of able young men raised on video games and trained as killers. There's 19-year-old Cpl. Harold James Trombley, whom Mr. Wright describes as curled over his machine gun, firing gleefully, and whom he quotes, as saying: ''I was just thinking one thing when we drove into that ambush. 'Grand Theft Auto: Vice City,' '' he says, referring to a video game. ''I felt like I was living it.'' Corporal Trombley, still in Falluja, could not be reached for comment.  But there is also Lt. Nathaniel Fick, a Dartmouth graduate, who joined the Marines, Mr. Wright writes, ''in a fit of idealism.''  After surviving an ambush, and Mr. Trombley's trigger finger, the marines were giddy. Ever conscious of the cultural ferment that produced this generation, Mr. Wright writes: ''Howling and laughing, they almost seem like Johnny Knoxville's posse of suburban white homies celebrating one of his more outrageously pointless 'Jackass' stunts.''  Underlying the narrative is Mr. Wright's admiration for the soldiers he accompanied, a sentiment that is, perhaps surprisingly, reciprocated. As a group, the marines from Bravo Company 2 of the First Reconnaissance Battalion have embraced his warts-and-all portrait, even though it has meant repercussions for several members of the platoon.  Sgt. Antonio Espera, for example, was reassigned from combat after the Rolling Stone articles were published. He said he did not regret speaking freely to Mr. Wright, who traveled carrying only pen and paper and a suit protecting against chemical weapons.  In describing the reality of war, ''I think he came as close as possible,'' Sergeant Espera said during a conversation at the apartment of Sgt. Eric Kocher, another marine portrayed in the book, who was home here healing after his arm was shattered by a rocket attack in Falluja in May. ''It's like reliving the war. I want people to know war isn't glamorous, that it's a last resort. War means war.''  He added: ''I risk my life trying to save civilians. We kill a lot of them, too. It looks bad, but if the population is too sensitive for war, then we shouldn't go.''  Sergeant Espera, who is Native American and Latino, was removed from his normal military assignment for comments he made to Mr. Wright about civilian casualties and the white man's ''manifest destiny.''  ''My C.O. said, 'After reading the article, I perceive you as a coward,' '' Sergeant Espera said. ''I was upset. The feeling around the battalion was I was a militant racist.'' He denies being a racist, and in the book Mr. Wright describes Sergeant Espera's evident closeness with his fellows, who are mostly white.  Sergeant Kocher, a fierce warrior-soldier with the word psycho tattooed inside his lower lip, was also disciplined for actions recounted by Mr. Wright, like running into a minefield to save a fellow marine. The reprimand rankled the enlisted men. In addition to his wounds, Sergeant Kocher has been suffering from the stress of battle; marines said they had seen him patrolling in a parking lot near his home.  Lately, the Marine command has revised its view of Mr. Wright's account, Sergeants Kocher and Espera said. They said the commander at First Reconnaissance had ordered his officers to read the book and the articles to get a clear idea of what war is like for enlisted men.  Major Douglas Powell, a Marine spokesman, said the members of the Marine Corps had not yet read the book, but added, ''I'm not aware of anyone raising a stink over anything in the articles in terms of accuracy.''  Mr. Wright won the unusually intense embedding assignment by hounding a commander in Kuwait City in the prelude to the war. The marines were not quick to warm up to a leftist rock-magazine journalist in their midst, referring to him only as ''the journalist.''  But fairly soon they came to respect the bravery (or foolishness) of this tall, often sheepish writer, especially because Mr. Wright seemed keen to ride into the most dangerous situations. They often had him ride ''on point,'' or in the lead vehicle, which normally draws enemy fire.  ''He was in the worst possible place to have a reporter,'' Sergeant Kocher said. ''During the first firefight, he took 10 rounds in his door.'' He added, with some admiration, ''After the first firefight, he didn't give up.''  Mr. Wright said a stubborn playground instinct had kicked in. ''Partly it was about not losing face,'' he said. ''I reverted to be like a 12-year-old on the playground. I wouldn't back down. And there were times when I knew we'd be shot at, and I'd fantasize about requesting getting taken out of being embedded. But then I'd make it through and not be injured, and I'd be flooded with this deep sense of, 'There's no way I'm leaving this.' ''  After his first experience of shelling, Mr. Wright, like all the marines, dug his nighttime sleeping hole deep. He grew a Marine-style mustache. And after several weeks, he was one of the guys. They particularly liked that he had once made a living writing for pornographic magazines.  ''His humor was the same, and he'd worked for Hustler, that was an automatic,'' Sergeant Espera said. ''If it was up to me, I'd have had him stand post.''  The book also details rising tensions between the men and a couple of their commanders, including Capt. David McGraw, whom the men referred to as Captain America. Mr. Wright describes the captain as firing randomly on several occasions, endangering his men and generally spreading panic.  Mr. Wright writes: ''One of the enlisted men in his vehicle challenges him. 'What are you shooting at?' he asks him.'' The marine then says, '' 'The guy is not right in the head.' '' Both comments are breaches of authority.  Later Mr. Wright writes of Captain McGraw poking a prisoner in the neck with a bayonet.  Mr. Wright's admiration for the marines runs deep. ''I really did fall in love them when I first met them,'' he said. ''I didn't want to be friends during the writing process. A reporter's motto is 'charm and betray.' But I didn't hide any of the warts. I was hard on them in the writing process. And I'm glad, because I like them.''  After a pause, he added, ''I was thinking of going back to Falluja.''  Sergeant Espera chimed in. ''I told him I'd just kick his butt here and save him the trouble,'' he said.
Article on Rolling Stone writer Evan Wright, who spent two months in Iraq with American Marines and has expanded three-part award-winning magazine article into book, Generation Kill; photos (M)