The Kite Runner

Amir flee's to San Francisco with his father. He eventually meets the daughter of an Afghan General and they get married. Amir's father dies shortly after the wedding, of what appears to be Cancer. Amir later finds out that his best friend Hassan was his father's son as well, after an affair with a local woman. Hassan had been killed when the Taliban stormed into Amir's father's house in which he was staying. Amir goes back to Kabul to rescue Hassan's son who has been taken by the Taliban. He rescues the boy and brings him back to the United States where he raises him as his own family. 
Thanks Brian!