pages 41 and 42, Amir and Hassan are faced with Assef, who has brass knuckles, and his friends,all of them bullies and older and larger than Amir and Hassan.  Hassan pulls out his slingshot and faces Assef down, saving Amir and himself from a beating, at the least.  His courage lies in the fact that he is scared, but still acts.  Amir sees Hassan's fear and says, "He was scared plenty" (42).

When Amir manipulates events so that Hassan is accused of stealing, Hassan admits to the deed, even though he knows that he and his father will be made to leave.  This was a courageous action, too.

Once Amir returns to Afghanistan, we see more courage on his part.  In fact, just returning to Afghanistan is courageous!  Two examples of his courageous actions are his taking on Assef, his Nemesis, after all those years, a man who clearly has great power and who nearly kills him and his taking Sohrab home to American with him.  The reunion with Assef, who still has his brass knuckles, takes place in Chapter 22, and Amir says he remembers very little of it, but he clearly endured great physical damage.  In a lovely piece of symmetry, what saved him was Sohrab, the son of Hassan, who has a slingshot, too, which he uses against Assef.

Why do you suppose Hassan exhibits great courage from the beginning and Amir does not?  It takes Amir nearly the entire book to become brave.  Surely, it cannot be because they are from different tribes?  They both have the same father.  What is the difference between them? 

KITE RUNNING.  While flying the kite is the more exhilarating and glamorous aspect, Hassan is happy to run the kite for Amir, and he perfects this side of the sport into an almost miraculous spectacle. Hassan can tell exactly where and when the defeated kite will descend, and

... may God--if He exists, that is--strike me blind if the kite didn't just drop into his outstretched arms.

Hassan refuses to give up the blue kite to Assef and his friends, willingly taking the consequences--rape and sodomy--in order to bring the kite home to Amir.

DEFENDING AMIR.  When the two boys are confronted by Assef and his young thugs on the street, Amir refuses to stand up to them, but Hassan defends them both with his trusty slingshot. His bravery saves both of them from a beating, but it draws the everlasting ire of Assef, who evens the score on the day of the kite-flying competition.

TAKING THE BLAME.  Hassan refuses to defend himself after he is accused of stealing the birthday gifts planted by Amir under his bed. He must have recognized that Amir had betrayed him, but Hassan is too honorable to shift the blame to his friend. He prefers to keep the truth secret from Baba, selflessly taking the blame himself to preserve Amir's honor.