For many Americans, what is shocking about the images of torture in Iraq's Abu Ghraib prison is not only their strangeness but also their familiarity, with echoes of internet porn and frat-house parties, David Levi Strauss tells Belinda McKeon.

Just over two years ago, the photographs began to emerge, burning images of torture and degradation into the memories of all who saw them. They showed Iraqi prisoners naked, bound, beaten, sexually humiliated, threatened by military dogs. One man's battered corpse lay sloppily packed in ice; he had not survived an interrogation. Over most of the scenes, American soldiers presided, grinning, pointing, often giving a thumbs-up sign to the camera.

But the most famous photograph of all was notable for its facelessness. A prisoner stood on a cardboard box, a conical black hood over his head, a black garment draped over his body, wires attached to his outstretched arms.

Immediately, it became the iconic image of Abu Ghraib. It seemed the fullest, starkest expression of everything that was wrong about the American presence in Iraq. It seemed simple; horribly, brutally, unforgettably simple - a portrait of man's inhumanity to man. But the critic and editor, David Levi Strauss, saw otherwise. Those pictures, which had been uploaded to the internet from the digital cameras of the soldiers in Abu Ghraib, were, he saw, deeply complex both in terms of their creation and their effect. And, in an effort to better understand that complexity, he has spent the last two years looking at the photographs in painstaking detail, thinking about every one. Not everyone, he knows, agrees with the logic of this.

"Certainly, to some people, what I do is an absurdity," he says, sitting at a vast desk in the well-stocked library of his home in upstate New York. "I mean, to spend all this time looking at single images. And writing on them, and belabouring every point. Some people would see that as beside the point, as not how images operate. Because one of the appeals and the seductions of images is that they appear to be instantaneous."

But, says Strauss, such close study of what appear, at first glance, to be mere - albeit horrific - snapshots can yield very interesting results.

"You get different kind of information, very different information from the kind that's instantaneous," he says.

STRAUSS IS AN experienced gatherer of fresh and sometimes astonishing information from apparently simple images. Along with those of the late Susan Sontag, his books and essays on the negotiations between aesthetics, identity and politics are among the most respected writings on photography. His most recent book, Between the Eyes (2003), dealt (like Sontag's Regarding the Pain of Others) with the role of the aesthetic in helping to communicate the reality of pain and violence. It included provocative essays on photography's relation to propaganda, on the changes wrought by September 11th in the production and reception of images, and on an idea with which he will grapple even more deeply in his next book: the believability of photographs.

In Dublin this week as part of the Arts Council's Critical Voices programme, he will, during a talk titled Breakdown in the Gray Room, ask his audience to rethink the way they have looked at the images from Abu Ghraib up to this point. He is interested, he says, not in the intent behind the photographs but in the effect. Though he confesses to having been curious about the trials of the accused soldiers, he believes that to focus on the intent, rather than on what the photographs are saying in a broader sense, is to do the official bidding, to go down the road of condemning "a few bad apples" while ignoring the larger picture that is muscling its way out through these pictures.

And the larger picture is complicated, Strauss argues. Because, as horrific and as strange as they were, these photographs, when viewed for the first time in the US, summoned up cultural archetypes unique to American identity. They contained within themselves traces of something all too recognisable.

"There was a bit of the uncanny to it," Strauss says. "It was a contradiction, because on the one hand, people didn't know what they were looking at, because they hadn't seen torture images like that before. But on the other . . . they were familiar. And this was the striking thing about them, that they moved into an image rhetoric that was familiar."

Strauss is talking partly about the impact on the American consciousness of do-it-yourself internet porn. The images from Abu Ghraib, he points out, were as much fantasy as they were reality, as much porn as they were atrocity, and there was nothing new about the poses, the acts, the positions into which the prisoners were forced.

But it wasn't just the echoes of porn which struck Strauss. It was those smiles on the faces of the soldiers, "that smile that's almost a grimace", as he describes it. He knew he had seen such smiles somewhere before, and it didn't take him long to identify where: in internet photographs of parties in university fraternity houses, in which smugly grinnng young men ruled over the unfortunates undergoing bizarre initiation ceremonies - including whippings, near-torture, mental and physical humiliation, even mock- hangings. And suddenly, something was unlocked. The photographs began to make sense.

"I think what's really happening in them," says Strauss, "is that the Iraqi detainees are being initiated."

The behaviour of the American soldiers, he explains, was characterised not just by cruelty but also by a strange frivolity. Mostly young and from poor backgrounds, they made the prison into their fraternity house.

"The attitude was often one of 'lighten up, we're having fun here, and you're a part of it. You're a part of us now'. This is a degraded form of those old rites that you find in traditional cultures everywhere, where there are rites of passage. And I think that's another reason why these things are legible to Americans . . . the whole motivation, the stated motivation, for the invasion of Iraq is that we're turning them into versions of ourselves. We're democratising them [goes the argument], and giving them what we have, and doesn't everyone want that? So they have to go through a little initiation to get there."

THE ABU GHRAIB photographs also had an extraordinary effect on what Strauss describes as the "hubris" of the Bush administration. He recalls with disbelief the sight of the photographs being carried into Congress in cases handcuffed to the arms of those carrying them.

"As if they could control them," he says. "They're digital. I mean, they were going out on e-mails everywhere."

Strauss shakes his head.

"But they thought they could control this. Because they have been able, since September 11th, to control images so effectively. I think that they were blindsided by Abu Ghraib. It was a big surprise to them."

Unsurprisingly, Strauss has also given long consideration to the images of September 11th, 2001. He believes that morning, the most photographed event in human history, when the eyes of the world were on the same scene, "reset the clock in our relations to images".

From the live coverage of the second plane going into the tower to the thousands of personal photographs that papered the walls of the city in the aftermath, to the way that newspapers and magazines began to use photographs differently from that day on, he says, "a lot of things that had seemed to have been resolved in our relation to images and their effects before that were just wiped out, wiped away".

Does he mean that the sights of that day changed forever the way we would look at images?

"They recovered an older approach," he says. "I'm convinced that, to understand our relationship to photographic images, to technical images, you really have to go back to long before they were invented, to a time when images were seen not so much as representations but as emanations, when they were seen, like Byzantine icons and religious images, not to have been made by hand, but to be a trace of the divine, of the real. To be actually divinely made."

This attitude has resurfaced, Strauss believes, in the way the photographic images allowed into the press are now viewed as unquestioningly as though the digital age, with all of its powers of manipulation, had never happened.

At least to some degree, Strauss is talking here about the nature and source of the images of the war in Iraq which are currently being fed to the American public, and about the way in which, as he puts it, "the American press pretty much turned over" and stopped asking difficult questions about this war. He hopes that the digital footage of soldiers and others living with the reality of the war, which is slowly finding its audience on the internet, will eventually reach "critical mass", but admits he is baffled as to why these images have not already made more of an impact in the mainstream media.

Yet whether or not this changes, there is one group which Strauss believes to have enormous responsibility in the current political climate.

"Artists and writers spend all of their time and have spent their whole lives looking at images and dealing with language," he says. "These are the two things which are being used to manipulate us and to form this new world that we're moving into. So I think it's only natural that artists and writers have a role to play."

For now, he says, autonomy from politics is not an option for the artist, even if it were ever really possible.

"Certainly it's possible, in this wealthy country, to abstract oneself, to pull back and to try to believe in a cloistered, autonomous world of art, but I think that's irresponsible now. At this point in time in history, in living where I do, I think that's not a viable choice."

• David Levi Strauss's Critical Voices talk will take place on Thur in the Irish Film Institute, Eustace Street, Dublin, at 5pm