For novelist John Katzenbach, it was a way of paying tribute to his father, Nicholas. If the name sounds familiar, it is because Nicholas Katzenbach was a major political figure during the sixties, serving as US Attorney General during the Johnson administration. Twenty years earlier, however, he had undergone an altogether different experience which had decisively shaped the rest of his life: he had been taken prisoner by the Germans and spent the remainder of the war in Stalag Luft III.

“As my father grew older,” recalls John, “I realised we had never really spoken about his POW ordeal, so I began asking questions about that period in his life. As a writer and storyteller, I started to see that some of the things he told me could be developed into an interesting and thrilling suspense story - a mystery. It wasn’t long before I sat down and wrote the opening lines of Hart’s War.”

Bruce Willis (with Colin Farrell in one of the film’s action scenes) plays the senior officer, Col McNamara, a third-generation soldier with a steely sense of honour.

What resulted from this was not your average prison camp story. Instead of focusing on heroic escape attempts or tales of torture and oppression, Katzenbach’s novel - and the movie starring Bruce Willis and Colin Farrell that is based on it - developed into a tense courtroom drama which deals, in a direct, accessible way, with such issues as honour, loyalty and truth. And the racism which continued to bedevil the US forces even in time of war.

Hart’s War is set during the final days of World War II, when the frantic Allied push through northern France and Belgium - the Battle of the Bulge - lead to endless confusion about where the front line lay and, as a result, the capture of US troops in unprecedented numbers.

Lieutenant Tommy Hart (Colin Farrell) is captured in just such a way - a jarring, shocking scene which sees him end up in a ditch full of corpses. Like Nicholas Katzenbach, Hart is a young law student attached to headquarters, and he is driving a senior officer on what should have been a routine mission. Suddenly, however, he finds himself surrounded by Germans. Thrown naked into a cold, dark cell, he is repeatedly interrogated, then eventually shipped off to a POW camp near Augsburg in southern Germany (the film was actually shot a little further to the north and east, outside the Czech capital of Prague).

In the camp, Hart finds himself cold-shouldered by the senior American officer, a third-generation West Pointer called Colonel McNamara (Bruce Willis), for reasons that eventually become humiliatingly clear to the young prisoner. Assigned to the hut run by Staff Sergeant Vic Bedford (Cole Hauser), who has created a power-base for himself within the camp in the same way that peace-time prisoners build mini-empires in jail, Hart soon finds himself also sharing his living quarters with two officers from the US Air Force’s only all-black squadron: Lieutenants Scott (Terrence Howard) and Archer (Vicellous Shannon). Bedford and the other enlisted men - many of them, like Bedford himself, from the South - treat the newcomers with hostility and contempt, and Hart’s interventions make little difference. This, after all, is 1944, and the ‘N’ word was very much a part of the everyday vocabulary.

Eventually, however, things go way beyond this. Archer is framed on a charge of possessing a weapon and shot by the Germans. Then, when Bedford is found dead, Scott is accused of his murder. With an agenda of his own, McNamara persuades the camp commandant (a career-making performance by Romanian actor Marcel Iures, recently also seen in another war-time drama: director Costa-Gavras’ controversial Amen) that there must be a court martial. And, again for reasons of his own, McNamara orders Hart to serve as counsel for the defence. It is that trial - and the events happening in parallel with it - that provide Hart’s War with its climax.