Leaving aside his controversial belief in Scientology, Tom Cruise is not best known for portraying spiritual characters. But as his new film,the Second World War epic Valkyrie opens in the UK at the end of the month, Cruise will be identified with the genuine article. The man he plays, Claus Schenk, Count von Stauffenberg, embodied rare qualities unfamiliar to our debased age, more used as it is to "heroes" whose sole heroism consists of kicking a ball into the back of a net.

It will also be a shock to filmgoers accustomed to seeing German officers only as unreconstructed baddies to watch a parade of British actors - Kenneth Branagh, Bill Nighy and even Eddie Izzard - supporting Cruise by playing the men in field grey as thoughtful, principled and self-sacrificing goodies. These are real heroes in thought, word and deed. And, however tainted by Hollywood vulgarisation Valkyrie may be, if the movie succeeds in showing a mass audience that not all Germans of the war generation were psychopathic sadists or monocled automata, it will have served some purpose.

Valkyrie was the codename for the military putsch triggered by Stauffenberg's intended assassination of Hitler on 20 July 1944. The plot's conspirators wanted to bring down the criminal Nazi regime, end Hitler's war, and usher in a new Germany built on principles of legality, democracy and - not least - Christian civilisation. But Stauffenberg failed. His bomb exploded, killing four members of the dictator's entourage, but not the Führer himself, who was left slightly injured and in an even more murderous mood than he had been before the blast. Stauffenberg's friends in Berlin, who were supposed to launch their coup simultaneously with the bomb, hesitated and dithered when they realised that Hitler had survived. They waited for three fatal hours for Stauffenberg to fly back to the capital from Hitler's HQ and take charge of the putsch. But by then it was too late.

Even though the putsch had been partially successful - in German-occupied Paris, Prague and Vienna the army conspirators arrested all the SS men in those cities without a shot being fired - elsewhere, as news that Hitler still lived spread, uncommitted or cowardly officers drew back and firmly placed themselves on the winning side. By nightfall, despite Stauffenberg's frantic effort to shore up support by telephone, the coup had collapsed. Stauffenberg and his four closest collaborators were summarily shot on the orders of one of these equivocating generals as the Nazis unleashed a vicious orgy of vengeance on all those who had dared lift hands against them.