The film: 'Truth is the first casualty of war,' reads the tagline for Redacted. Based on US soldiers' gang rape, murder and burning of a 14-year-old Iraqi girl in March 2006, and their murder of her parents and younger sister, Brian De Palma's film echoes his 1989 picture Casualties of War, about GIs keeping a Vietnamese girl as a sex slave and then killing her to cover their tracks.

Like Paul Haggis' In the Valley of Elah, the film explores how humanity is forgotten when young men are exposed to the extremes of modern warfare, and how their regard for human life is negligible when given carte blanche to lord it over others.

Redacted sees De Palma rail against the excesses of power, his anger directed more towards the cynical schemers in Washington than the soldiers, as the film shows how the ranks are filled with working class youngsters looking for a way out of their miserable circumstances (Salazar [Izzy Diaz], for instance, says he joined the army to get the money to attend film school, which has rejected him once before anyway).

It's the way that De Palma (right) tackles the story that's more controversial. Intent on examining how to get to the 'truth' of what's happening 'out there', the director shuns the conventions of Hollywood and delivers the story - with a cast of unknowns - through an amalgamation of digital video footage (shot by Salazar for his video diary), sequences shot documentary-style (complete with slick cinematography, sweeping music and a solemn voiceover), surveillance footage and video streamed from American and jihadist websites.

But what makes Redacted an intriguing premise isn't just this technological experimentation. Keeping his distance from the commercial demands of the big studios (the picture was financed by the comparatively independent Magnolia Films), De Palma was able to shun high drama and inject into the screenplay a battery of questions about the cynicism behind American interventionism and its terrible human cost to young, working-class Americans and all Iraqis. And if the film fails to bring home that message, there's a montage of real pictures of Iraqi men and women who've been killed in the war - a shocking reality check if ever there was one.

The extras: De Palma articulates his aspirations further in an interview, in which he says his film shows 'how a normal human being would behave in a very crazy situation', and contrasts the war in Iraq with the one in Vietnam (the absence of drugs, alcohol and women in Iraq, he says, creates levels of frustration that can explode with dire results).

A short behind-the-scenes segment revolves around the shooting of the card-game scene in which the protagonists' murderous plot is hatched. The one feature that warrants attention, however, is the series of extensive interviews with Iraqi refugees who attended a screening of the film in the Jordanian capital Amman. They are indisputably the casualties of the war, as they mourn their exile and the way 'Iraq is gone'.

The verdict: Challenging fare that explores the fallout of the war in Iraq in the most vivid way.