Assef is certainly one of the most interesting characters in The Kite Runner. Like Amir and Baba, Assef and his father are neighbors and Pashtuns, the dominant ethnic group of Afghanistan; they are also Sunni Muslims. Assef's father, an airline pilot, is a wealthy friend of Baba's, but Assef and Amir are not friends: Assef is a sociopathic bully who idolizes Adolf Hitler. Assef's mother is German--thus the origin of Assef's blonde hair and blue eyes--but she has not provided her son with his love of The Fuhrer. When Amir calls Hitler "crazy," Assef tells him that
"He sounds like my mother, and she's German; she should know better."
Unlike Baba and Amir, who have grown up with Ali and Hassan as their playmates, Assef hates Hazaras, and he never fails to insult Hassan when they meet. He grows to hate Hassan even more when Hassan stands up to him, threatening him with his slingshot. But Assef makes Hassan pay deeply when he catches him alone following the kite fighting contest, and gleefully sodomizes him, claiming to his friends that
"... there's nothing sinful about teaching a lesson to a disrespectful donkey... It's just a Hazara."
Assef and Baba do share one characteristic: They both hate the Russians. While Baba curses them back in California--Assef is busy torturing and killing them in Afghanistan. Much later, Assef will participate in the mass murder of Hassan's kinsmen after Assef joins the Taliban, a group which not only hates Hazaras and Shi'a Muslims, but who also hates moderate Sunnis. For Assef, Afghanistan is the perfect place for him to carry out his hatred and murderous ways: It has become
"... a beautiful mansion littered with garbage, and someone has to take out the garbage."