Sam Mendes’s name for his film is right. It hits you in the face with the mud, blood and gloom that was there, heavily, relentlessly, during that terrible year following three years of horror and followed by an even worse one. Out of this war that Mendes described as “a chaos of mismanagement and tragedy,” he has made a war movie like none other. Eschewing regular scripts for war films, the storyline is about how to stop a battle