Two films in ten years is a meagre output by any filmmaking standard. But then American writer-director Kimberly Peirce’s striking 1999 debut, Boy’s Don’t Cry, won an Oscar, and her belated follow-up, Stop-Loss, might be the first film about Iraq to really engage a cinema-going crowd. So Peirce’s batting average is pretty good.

The new film dramatises the plight of US soldiers returning from Iraq, their tour of duty done, their minds and bodies scarred from combat, only to be returned to the front line courtesy of the Bush administration’s involuntary re-enlistment policy widely known as the ‘back-door draft’. It’s an angry protest film, but an entertaining one, designed to reach an audience. And it began life seven years ago, immediately after the twin towers struck the World Trade Centre.

‘After 9/11 my younger brother enlisted in the Army,’ Peirce says. ‘I understood his motivation, but the thought of him doing this was devastating. In an effort to understand what he was going through I started to make a documentary about our soldiers, and during the course of interviewing many of them it became clear there was a great deal of discontent about how the war was being fought.’

She continues: ‘With enlistment rates falling, the Department of Defense invoked its Stop-Loss policy and the military began to forcibly re-enlist Iraq veterans, about 81,000 I discovered, which led to soldiers taking legal action. When that didn’t work they started going AWOL.’

Sometime in 2004 Peirce decided to turn her documentary into a feature that would hang the story of a group of young soldiers from Texas on their reaction to the back-door draft. Peirce developed the script with co-writer Mark Richard, whom she’d been introduced to by mutual pal Charlize Theron and with whom she’d adapted his yet-to-be filmed story, The Ice at the End of the World. The pair opted to work outside the studio system due to the bad experience Peirce suffered working on her abortive second film, Silent Star. By the time the script was complete, Hollywood had begun in earnest to greenlight projects about Iraq, and although neither Lions for Lambs, nor In the Valley of Elah had played very well at the box office Peirce got the heads up from Paramount.

Stop-Loss has done respectable business in America, but more importantly for its maker it has appealed to the people it’s about. ‘I’ve had veterans and the families of veterans approach me and say they are glad their story has been told in this film,’ says Peirce. ‘These young men and women have a sense of duty, so they sign up to serve their country. But their patriotism is turned upside down when they’re faced with impossible circumstances in Iraq and they end up committing acts that force them to question who they are and what they believe in. I’m glad to have had the opportunity to tell their story.’

Stop-Loss is on general release from Fri 25 Apr.