Basically this movie was a project of German producer Wolf C. Hartwig, who had made millions with his soft-core exploitation movies. He had been dreaming of a movie about Hitler's campaign into Russia, told from the German viewpoint, but nobody was interested in making such a movie. Things changed after Sam Peckinpah had shown some interest in the project.
Cross of Iron is set in 1943. The Russian campaign has turned into a drama and the Germans are on the run. Corporal Steiner is the leader of a small regiment of fire-eating soldiers; he's a bit of a nuisance, but he has saved the life of a few officers, who now close their eyes for his rebellious behaviour. A new situation is created with the arrival of a new commander, a Prussian officer, colonel Stransky, who volunteered for the eastern front because he wants to earn an Iron Cross at all costs. The Iron Cross is awarded for bravery, and his family wouldn't ever forgive him if he came home without one. When a Russian attack on the camp is beaten off, Stransky sustains he had led the counter-attack, and therefore deserves the Iron Cross. Steiner knows he's lying ...
In 1977 Peckinpah was still a big name, but alcohol and cocaine addictions had ruined his health and he could only concentrate for a couple of hours each day. Cross of Iron is a work of a director who was way over his peak. Admittedly there are a couple of great things in it: the opening credits (the children's song Hänschen Klein and the Horst Wessel song played over black & white footage turning red) are marvellous, almost hypnotizing, and Peckinpah hadn't lost his touch for action scenes completely; some of them, especially those with tanks, are genuinely exciting. But the film has a sort of intoxicated feel hanging over it: it has its bright moments, but most of it is a blur. What had been subtle in The Wild Bunch, looks crude here. Moreover virtually every character is a cliché. We get them all: the brave but headstrong sergeant, the arrogant Prussian officer, the knowing general who understands the war is lost, the sadistic Nazi-member, the young and naive soldier, the heroic lieutenant who dies in battle, etc.
Performances vary, partly due to some awful dialogue lines. Maximilian Schell is quite good as the Prussian rat, who absolutely needs his sign of bravery, but otherwise I thought the German actors in supporting roles were more convincing than some of the 'stars'. In spite of some large-scale action scenes, the film works best in its more intimate moments (like the scene with the soldier who was left alone for three hours in a bunker after all his comrades were slaughtered).