Like the army his film portrays, Sam Peckinpah was in retreat by the time he made "Cross of Iron" and many consider this his last stand, a final counter-attack before the rout that was "Convoy". Following the commercial and critical failures of "Pat Garrett and Billy the Kid" and "Bring Me the Head of Alfredo Garcia", he'd been forced to prostitute himself and turn in the lacklustre "The Killer Elite". But not only that, his various addictions were starting to get the better of him and have a serious effect on his professional output. So the miraculous thing is that "Cross of Iron" is almost a return to his previous blistering form and certainly ranks amongst his best films.
James Coburn's career was also on the slide by this time and in much the same way as his director, he found it in himself to give a performance which I've read he considered his best. The rest of the cast are pretty well pitch-perfect too: Maximillian Schell as Captain Stransky, whose arrogance is only matched by his cowardice; James Mason as war-weary Colonel Brandt; David Warner as the incontinent cynic Captain Kiesel; and Senta Berger in a notably unambiguous part for a Peckinpah woman as Nurse Eva.
The action might be bloody, at times wincingly so, but what emerges through all the smoke and gore is the tragedy of men who are at odds with what they're doing and yet have no other existence, something understood by Eva who says to the departing Steiner, "Are you afraid what you'd be without it (the war)?"
As to whether this film deserves five stars or only four, the answer is probably four and a half, the missing half star due to narrative confusion at one point and the mish-mash of accents, some British, some German and one American. However, these are small points, since what the viewer will take away with him are memories of so-vivid-you're-almost-there battle scenes and the aching sense of doom that lingers over all the characters.
One point of trivia: this is the only Peckinpah film to spawn a sequel, the seldom seen "Sergeant Steiner" made the following year with Richard Burton in the title role.