Answer 1: Amir claims to use America to "bury my memories," whereas, for Baba, it is a place "to mourn his." Amir embraces America and all it has to offer as a means to escape the ghost of Hassan that was haunting his life in Afghanistan. (you have to include the quotes from the story)
Answer 2: No longer was he a powerful and respected man that he was in Afghanistan. In America, he works menial jobs. He feels second class and impotent. For Baba there is no trust and honour in America.
Question: Is there a story you are supposed to read for this?
Best I could do.