Harsh Pressures of War
War influenced people to do many inhumane things, the most prevalent of which was being a sort of monster. Many Nazi's were innocent in their own sense, but collectively, they became an unstoppable force that unleashed hatred to everyone else. Helen was one of the victims of war, and has since lived her life with its large scar. Her husband, Siegfried, died meaninglessly in the war, while Alfons was a successful officer that helped kill many people.
Morals
Ever since he was young, Alfons had been around the forces of evil. Becoming a member of the Hitler Youth Organization, he learned to fight like an automaton. It wasn't until the war was over and he had a chance to reflect on what he had done did he realize that it was all wrong. There was no reason to discriminate against the Jews, and there were countless meaningless deaths because of the war. Alfons now feels like an outcast for what he has done, and lives in the United States, where he writes a newspaper story on his role in the war. He meets Helen again, and he explains how the war taught him the difference between right and wrong.
Social Hierarchy
Seen throughout history, in many places, it doesn't quite matter where you are from, but the family that you are born into. Somewhere along the line, someone came up with the convoluted idea that children and their parents are extremely alike - so much so, that children will never be able to rise up above what their parents did - or below. This is sort of what happens in this novel. Helen lives in a Jewish family, and is discriminated because of her beliefs. Alfons, however, became a member of Hitler Youth as a young child and was important in the war effort. Although the two grew up in the same neighborhood, they lived completely different lives because of their social and ethnic backgrounds.