'IS IT possible for a photograph to change the world?" muses Errol Morris at the beginning of Standard Operating Procedure, his film about the soldiers convicted of torturing prisoners at the notorious Abu Ghraib prison in Iraq. It is four years since those photographs of near-naked men with bags over their heads — one on the end of a leash, one standing on a box with wires attached to him — were released into the world, but nobody who saw them will forget them easily. They were brutal and sordid. Those photographs, says Morris, "changed the war in Iraq and changed America's image of itself".

These are heady times for Hollywood, traditionally a Democratic heartland. There is a hugely unpopular war going on. The next president is likely not only to be a Democrat, but a Democratic president unlike any of his predecessors. If movies can change anything, now should be their moment. But while occasional commentaries remark on the slew of films coming out against the war in Iraq — about a dozen were slated over the past 18 months — the average cinema-goer is unlikely to have noticed.

The big film of recent weeks, for example, was the latest Indiana Jones, set in a period that allows Indy to be pitted against the traditional — if now meaningless — Soviet menace. Before that, Americans flocked to see Robert Downey jnr's Iron Man defeat some evil characters in the pebbled uplands of Afghanistan. The pesky foreigners are trying to assemble their own nuclear arsenal with illegal American imports; Iron Man explodes a fair few of them and order is restored. This doesn't suggest America's image of itself has changed much at all. Not in the multiplexes, anyway.

And it's true that the film-makers trying to confront the Iraq war experience have, on the whole, found it a tricky business. The rash of political films we hear about certainly exists, but they have largely been buried or ignored; this war, it seems, is not good entertainment, even with stars attached. Rendition, with Reese Witherspoon, Meryl Streep and Alan Arkin — about the kidnap of an Egyptian-American by US authorities who believe he's a terrorist — took only $US23 million ($A24 million) in its worldwide theatrical release. Robert Redford's Lions for Lambs, a courtroom drama about US troops in Afghanistan, barely made its budget and publicity costs back.

A Mighty Heart, Michael Winterbottom's film about a kidnapped US journalist, had Angelina Jolie in the lead but had a limited release; Nick Broomfield's Battle for Haditha, which was made with American and Iraqi non-professional actors, was even smaller. In the Valley of Elah was written and directed by Paul Haggis, whose previous film, Crash, won the Oscar for best picture. However, its grim story of a father piecing together his vanished son's Iraq story did not attract an audience, even with Tommy Lee Jones and Charlize Theron in lead roles.

Inevitably, these films are compared with the anti-Vietnam pantheon of Apocalypse Now, The Deer Hunter, Coming Home, Born on the Fourth of July and Platoon, all of which won Oscars. These films, however, all came out well after America's involvement in that war had ended and there had been a period of generally appalled reflection on it. Films contemporary with the Vietnam War that resonated strongly with the anti-war movement, such as MASH and Catch-22, were black comedies set in Korea and during the Second World War respectively: they tackled the horror with irony and by setting it at a distance. The fact that the current crop is commenting, as far as possible, on something happening right here and now — even if their impact has so far been limited — is noteworthy in itself. The subject matter is unpalatable because it is so urgent.

And while the masses have so far stayed away from them, they have had enough impact to draw the ire of America's virulent right wing. Brian De Palma, who has previously directed such major films as Scarface, Body Double and the Vietnam post-mortem Casualties of War, last year made a low-budget film about Iraq using non-actors and the quick, cheap technology of high-definition cameras. Redacted reconstructed, in fictional form, a real incident two years ago in which a group of US soldiers raped, murdered and burned a 14-year-old Iraqi girl and her family.

It won him a Silver Lion at the Venice Film Festival, but at home he was reviled, in the words of Fox News shock-jock Bill O'Reilly, as "a true villain in our country" who should be imprisoned for treason. Haggis, meanwhile, was accused of making "Bin Laden cinema"; right-wing groups called for a boycott of In the Valley of Elah. Both films, however, were based almost entirely on material produced by soldiers themselves that the directors found on the internet.

Nobody can say the monstrosities they show didn't happen. But while jingoists may argue that they should not be mentioned, the common theme of all these films is an attempt to understand how apparently ordinary, decent men and women come to post online pictures of themselves playing with bits of burned Iraqi corpses. "When you have a terrible crime," De Palma said of his film, "you want to know how these boys were brought to do this."

Both filmmakers and critics are often asked whether a film can change the world. Morris is one of the few who has evidence that it can, at least in a very specific way. In 1988, he became legendary among documentary buffs for his film The Thin Blue Line, a meticulous dissection of the murder of a police officer for which a drifter had been wrongly convicted. On the strength of the evidence Morris had assembled, the case was reopened and the man exonerated.

Standard Operating Procedure is similarly precise. Without knowing entirely what he was going to do, Morris began interviewing the former brigadier-general in charge of the 800th Military Police Brigade at Abu Ghraib, Janis Karpinski, who had been relieved of her command and demoted by President Bush. He talked to her for 17 hours over two days. After that, he set about finding the so-called "seven bad apples" who were indicted after CBS broadcast 12 of the torture pictures.

Although he was making a straight documentary, his quest was similar to De Palma's. "I felt it was a story I needed to tell. The media and the government had provided little information about these soldiers. Who were they? Why did they do what they did?" To explain, he emphasises, is not to excuse. "People get confused. They think to capture moral complexity is to exonerate or to absolve, which is, of course, not the case. It's simply to capture the moral complexity."

Several of these filmmakers are also keenly aware of filling a gap. "Where are the pictures?" says De Palma rhetorically. "If we are going to finance the bombing and destruction of a country, I'd like to see the pictures from it."

In an age of embedded reporting and extensive syndication of limited material, he says, the sorts of horrific images seen on nightly reports of Vietnam no longer make it into mainstream media. "That was the lesson the US government learned from Vietnam," says De Palma. "If you're going to fight an unpopular war, make sure photographs of scorched girls running for their lives don't reach the public."

"I'm always interested not so much why things are investigated but why they aren't investigated, why people don't pay attention to them," Morris says.

His film, of course, is entirely about pictures. There is an irony, he says, in the fact that without the photographs taken by US Army Specialist Sabrina Harman, who subsequently spent six months in prison for her misdeeds, there would be no record of the death of Manadel al-Jamadi during a CIA interrogation. "She rendered this amazing public service by taking these pictures."

As he made the film, however, he reflected that photographs — the evidence of one's eyes — could actually shut down inquiry because they seemed definitive. "Pictures can be both expose and cover-up at the same time," he says. "You look at the picture; you are shocked, you are disturbed, you are angry. But you don't see the children kidnapped and held as hostages in Abu Ghraib; you don't see the tent cities with literally thousands of prisoners loaded in trucks in almost random searches and seizures. You don't see the foul bureaucratic apparatus that allows very few people ever to get out."

It is also true, he says, that the military was able to turn the disastrous expose of the soldiers' snapshots into a story of how the country had been betrayed by these so-called bad apples. "The war goes south, the insurgency grows, the Arab world hates us, everything is out of control — you want to blame someone; don't blame the administration, blame these guys."

Just after his film was launched at the Berlin Film Festival, where it won a special jury prize, a paragraph in a German newspaper mentioned that Bush had just said techniques such as waterboarding, where detainees are partially drowned, were indeed legitimate interrogation tactics. It was business as usual. Whether a photograph (or a film) can change the world is still a question up for debate.

Redacted will screen at this month's Melbourne International Film Festival. Standard Operating Procedure will be on limited general release from Thursday.