The Last Train.

A fat middle-aged man in German officer's uniform gets off a train somewhere in Russia in winter. He is a doctor who has just been called up we learn eventually. This is the end of the line- the Germans are about to retreat. He goes to a hospital which is being evacuated and is thrown out. Kicked out he wanders with another conscript- a failed actor turned postman. The postman is deafened by a shell explosion. They meet their Russian equivalents, others as bad at killing as they are, while other Russians and Germans kill one another around them.