Betraying someone can be hard on them. Hassan had betrayed himself and Amir had betrayed Hassan. "A loyal Hazara, loyal as a dog." Hassan has betrayed his confidence. Now, Hassan is being betrayed by Amir. "Maybe Hassan was the price I had to pay, the lamb, I had to slay, to win Baba." Amir's guilt is so overwhelming, that he made it look like Hassan was guilty. No one should betray anyone.
Some people think betraying is okay but its not. Amir just keeps doing it. "I lifted Hassan's mattress and planted my new watch and handful of Afghani bills under it." He betrays him again in order to get his father to fire both Hassan and Ali. Amir now puts Sohrab in a orphanage even though he said he wouldn't. "You promised you'd never put in one of those places." Amir had promised Sohrab that he could live with him after Hassan passed away, but instead, made him go to a orphanage. People shouldn't like to betray others.
When something is wrong, we should help out. Amir didn't help out his best friend. "Hassan didn't even struggle, didn't even whimper." Amir then ran away and didn't stop to help Hassan. He could've called for help, but he didn't. "I stopped watching, turned away from the alley." When Amir could've done something useful, he didn't. Amir likes betraying peopled its not right.