“You don’t know what it’s like here,” said Shmuel eventually in a low voice, his words barely carrying across to Bruno. “You don’t have any sisters, do you?” asked Bruno quickly, pretending he hadn’t heard that because then he wouldn’t have to answer.

Bruno does not know how to confront the atrocities of Shmuel’s life in Auschwitz, so he makes a habit of changing the subject. Despite the narrator’s repeated insistence that Bruno always tries to be honest with himself, he avoids confronting the reality of Shmuel’s tragic circumstances. Bruno takes quite a while to realize how much he might hurt his friend when he avoids the trickier topics in their conversations.

Bruno from time to time glanced back in the direction of his sister and the young soldier and felt a great urge to go back there and pull Gretel away, despite the face that she was annoying and self-centered and mean to him most of the time . . . he hated the idea of leaving her alone with a man like Lieutenant Kotler.

Early in their time at Out-With, Bruno’s main reason for disliking Lieutenant Kotler is because he feels belittled by Kotler. However, even before Kotler shows the full extent of his violence, Bruno senses that he is “just plain nasty” and feels like he betrays Gretel by leaving her alone with Kotler. Kotler never directly harms Gretel, even though his leaving breaks her heart, but the novel strongly implies that he could hurt Gretel or any member of the family if he felt they were a threat to Hitler’s agenda. Even without understanding the full picture, Bruno has a gut feeling that Kotler is not a good person and regrets not trying to keep Gretel away. By the time Kotler shows his true colors, he is so entrenched in their family it would be difficult for Bruno to voice his misgivings.

Lietunant Kotler grew very angry with Pavel, and no one – not Bruno, not Gretel, not Mother and not even Father – stepped in to stop him doing what he did next, even though none of them could watch.

Each member of Bruno’s family is distinctly uncomfortable with the way Kotler treats Pavel. Had they stepped in or even spoken up against Kotler’s violence, they could have outnumbered the individual Kotler and prevented his cruelty. Father especially would have influence as Kotler’s superior officer. If Father commanded Kotler to stop abusing Pavel, it would be insubordination for Kotler to continue, and he would face consequences as a result. Father and the rest of Bruno’s family would have power in this situation if they chose to use it, but they instead remain silent and Pavel suffers the consequences.

[Bruno] had never felt so ashamed in his life; he had never imagined that he could behave so cruelly. He wondered how a boy who thought he was a good person really could act in such a cowardly way towards a friend.

Bruno is ashamed after he denies being friends with Shmuel and giving him food. Bruno was afraid Lieutenant Kotler would punish him and chose to protect himself rather than his friend. Afterward, Bruno describes first his silence and then his denial as cruelty. He does not call it a mistake or neglect, but active, actual cruelty. Although Kotler is the one to physically harm Shmuel, Bruno knows he should have stood up for his friend and tried to protect him. Bruno recognizes that his silence contributes to Shmuel’s harm just as much as Kotler’s malice.

“You wear the right outfit and you feel like the person you’re pretending to be . . . that’s what I’m doing . . .  pretending to be a person from the other side of the fence.” 

“A Jew, you mean,” said Shmuel.

Even when he walks into Auschwitz, Bruno doesn’t really know what it means to be a Jew. All he knows about Jewish people is that they live on the other side of the fence, and the Germans supposedly don’t like them. And yet, it is far easier for Bruno to think of wearing a “costume” than it is to confront the very real experience Shmuel lives as a Jew in a concentration camp. It is only after Shmuel openly names his community that Bruno begins to understand he might be getting in over his head. The difference between a person from the other side of the fence and a Jew to Bruno is something conceptual versus something real. Shmuel’s openness and insistence on naming who he is forces Bruno to realize that Shmuel’s life and the things he has described are real, even if neither boy fully understands them.