What does his father mean when he says we are correcting history in the boy striped pajamas?

The father in The Boy in the Striped Pajamas refers to the Nazi regime's efforts to alter the historical record to fit their ideology. This includes the erasure of Jewish people and other minorities from society, as well as the glorification of the Aryan race. The father is complicit in this process and believes that it is necessary for the greater good of Germany. He justifies his actions by claiming that the Jews are a threat to Germany and that they are unfit to live in the same society as Aryans. However, the novel suggests that the father's actions are ultimately harmful and that they contribute to the Nazi regime's downfall.