'THERE is no such thing as a private life, " says Virginia Kindwall, the half-Japanese, half-American heroine of Anthony Swofford's debut novel, Exit A, "all lives are public." While this statement might suggest the point where George Orwell and Andy Warhol meet, it's a downside of success for the author, who achieved worldwide fame in 2003 with Jarhead, a memoir of his time as a Scout Sniper with the United States Marine Corps during the first Gulf War. So does he think this is true? Did his own life become public property in the wake of such a success?

"It certainly reverberated. But that's what happens when you write a memoir. You sit alone in a room and you don't really think about readers and then suddenly you meet strangers who say 'how's your sister doing?' and you realise that you wrote something about her. That's the kind of exposure I wasn't necessarily prepared for."

He may not have been prepared for it, but Swofford had been planning a career as a writer since he was a young man, although his four years' service as a US marine put a temporary hold on his plans. "I wanted to be a writer as a teenager. I was a reader and a loner, all those things that help make a writer, but I didn't have the right influences around me to really guide me and it wasn't until a couple of years later, when I was at college, that my desire to be a writer was rekindled through learning and having careful, thoughtful mentors. I wrote collections of short stories that were mostly about the Marine Corps and the Gulf War, but they were not at all autobiographical. I call myself a reluctant memoirist. Finally I realised that to write the most compelling narrative book about the Marine Corps and the war, I would have to tell my own story."

It's hard to imagine Swofford sitting in the desert considering a future built around novels and book tours but it appears his artistic interests created a distance between him and his fellow jarheads. "I was reading Camus, " he recalls. "And Shakespeare.

And they were like, 'we did that shit at high school.' My desire to learn was never tampered with but it certainly wasn't encouraged either. Reading was a link to my former life and a reminder I was only going to be in the Marines for four years, that I would get out and become educated and pursue a different kind of life."

In person, the 35-year-old Swofford comes across as affable, relaxed and more responsive to questioning than I had expected, having read the interviews he did around the time of the Jarheadmovie. "I was absolutely exhausted then, " he admits. "I was like, I don't want to hear the words Jarhead or Anthony Swofford ever again." Having lived on a US airbase in Tachikawa as a child, he recreates that setting in the Yokota airbase outside Tokyo where the 17-year-old hero of Exit A, Severin Boxx, is experiencing the pangs of first love while simultaneously turning against the military authority that dominates his domestic life. NonAmericans reading the novel cannot help but wonder how the local people respond to the presence of a foreign military power in their country.

"It's very complicated, " he explains. "The economy benefits because the GIs come off the base and they drink in the bars and they spend their money in the shops, so it can help in terms of economic vibrancy. The community around it certainly reaps some rewards but I think it also suffers some. It's an uneasy balance. Many Japanese would say that Japan hasn't been invaded by North Korea or China because America's there. And there's a pretty good argument for that."

Trying to engage Swofford in a political debate is a lot more difficult than asking him to discuss his fiction. While he appears to have reservations about America's military dominance and its continuing presence in Iraq, he seems uncomfortable at the notion of criticising his country too strongly; he's patriotic, he chooses his words carefully but one can sense a certain unease. "I think the world does look to America to lead in many ways, " he suggests to me. "And sometimes America fails. Sometimes America is cocky and too sure of itself and I think we're seeing in Iraq a result of that. A lack of diplomacy and an unwillingness to listen to other voices and consider world opinion." And yet that is a military force to which he devoted himself for four years, to which he gave his allegiance.

"Yes, but I was ashamed of who I was. I was ashamed of that urge for violence, that urge towards brutality, that desire to kill.

There are many ways in which Jarhead was a kind of apologia for who I was, but it also contains an understanding of how I was made." I suggest that if that's the case, it's only those who have been through such an experience who can understand that shame;

you can criticise your family but no one else can. "Exactly. Or your good friend can call you a jarhead and someone else calls you a jarhead and you get in a fistfight."

Both of Swofford's books treat the American military force as a sleeping tiger, continually preparing to fight but lying dormant in the meantime. "That's part of the nature of the military, " he tells me. "There was a number of times when I was in the Marine Corps when it was ok, we're going to war in the Philippines, let's go guys and then? oh sorry, stand down for 72 hours. I think that happened three or four times. But war is a rich pageant for a writer. There's courage and cowardice and love and hatred and anger and death, but it won't be the only place that my books visit."

It's clear from his conversation that Swofford is excited by the literary opportunities Jarhead has afforded him. His sentences are peppered with references to other writers, to books that have influenced him, teachers who have encouraged him. But although he has achieved his greatest success with a work of non-fiction, his heart clearly lies with the novel. "For me, the act of writing is sculpture. I have the raw material, it's there. You're creating characters and you have to know everything about them.

The stuff that doesn't go into the book, you still must know. You need to know what their fifth birthday was like, even though it's not in the book. And that's a different kind of discipline."

Films play a substantial part in both books; the marines endlessly discuss war movies in Jarhead, and key scenes in Exit A take place while the protagonists are watching Bonnie & Clyde over and over. (That movie's star, Faye Dunaway, even makes a startling cameo appearance towards the end. ) I wonder how he reacted to seeing his own book, and by extension his own personal military experiences, portrayed on screen by Jake Gyllenhaal in Sam Mendes's 2005 movie?

"I admire the film, " he says cheerfully. "I think it's a really smart and artful adaptation. He found the emotional centre, the psychological and metaphysical centre of the book on screen.

Some of the edge from the end of the book is not there in the film, some of the anger is not on the screen and that's probably the only place where the film is lacking."

Is that anger the reason so many people responded to Jarhead?

"I think it resonated because the Anthony Swofford that you meet in the pages is not necessarily an attractive young man, " he admits. "I'm not sure that I'd want to spend any time around him because he'd probably kick my ass. I could have prettied myself up. I could have -" "Become like Jake Gyllenhaal?" I venture.

"My mother thinks I'm more handsome than Jake Gyllenhaal, " he smiles. "But that's just my mother."