What are the key themes in "The Boy with the Striped Pajamas?"Why are these themes important to the novel as a whole?

In the novel, “The Boy in the Striped Pajamas,” by John Boyne, there are a couple of major themes that run throughout the story.  Bruno, a lonely little boy is the protagonist in this story.  He has an older sister named Gretel, a nanny and house keeper named Maria, a mother and a father.  Bruno’s father is a Commandant of a Jewish concentration camp.   The major theme is the desire for friendship.  Boyne explores the theme of friendship by having Bruno wander to the fence of the camp, and he meets another boy his age.  The problem is that this little boy, Shmuel, is a prisoner.   He is a Polish Jew who is interned at Auschwitz along with his family.   The boys become friends from opposite sides of the fence and the war.  The desire in these two boys for a friendship is so strong that they ignore the fence between them.  They become very dependent upon one another.  This friendship will eventually lead to tragedy.

When Bruno’s father asks him about how he knows about the people in the stripped clothes, Bruno tells him that he has seen them from his window.  Bruno's father forbids Bruno to go near the fence, and tells him to play near the house. Bruno doesn’t understand his father’s hatred of these people.  We also meet a violent and hateful soldier who comes on to Bruno’s older sister.  However, we see his violent hatred of Jews when he beats a prisoner who works in the house.  He also threatens and intimidates Bruno.  The actions of the Nazi soldiers and Bruno’s father demonstrate the theme of prejudice that runs throughout the novel.

"'The Boy in the Striped Pajamas' explores the beauty of a child's innocence in a time of war, the common desire we all have for friendship, and the fences—both literal and figurative—that we must all navigate and choose whether or not to break down."