Chapter 5

In this chapter, Amir and Hassan's conversation is interrupted by a loud roaring noise and the sound of gunfire. This is the coup as they overthrow the king of Afghanistan.
Amir and Hassan retreat to their tree as they try to distract themselves from the events. On the way, they run into the three bullies, Assef, Wali and Kamal, who question Amir about having a Hazara friend. Hassan then scares the bullies off with his slingshot, but Assef promises revenge.
As life returns to normal after the coup, Baba arranges for Hassan's birthday to have his cleft-lip fixed. Amir then foreshadows events by informing us that 'that was the winter that Hassan stopped smiling.'
At the beginning of the chapter the loud noises are a sign that Amir's life is changing along with the rest of Kabul. It could be seen as the true start of Amir's story with chapters 1-4 introducing characters and setting the scene. In this chapter, Amir's older and more mature self fades into the background of the narration and it continues in a somewhat childlike tone of Amir's younger self.
This is also the chapter in which Afghanistan changes from the traditional country Amir has talked about to the modern war-torn country which we as readers are more familiar with. Amir comments as the gunfire and explosions sound outside their house. 'They were foreign sounds to us then [...] Huddled together in the dining room [...] none of us had any notion that a way of life had ended.' The sounds of the coup are the start of a process which leads to three decades of war.
The behavior of Assef and his gang begins to change Amir's relationship with Hassan. The bullies represent the first real outside threat to Amir's previously comfortable life. Assef introduces himself followed by calling Amir a 'fag'. This creates a feeling of sexula threat which always accompanies Assef's role in the novel and foreshadows events to come.
The fact that Amir allows Hassan to stand up for him reinforces the idea that Amir lacks self-confidence and the traditional 'macho' characteristics. It also widens the growing gap in Amir and Hassan's relationship with Amir's thought, 'He's not my friend! [...] He's my servant!' showing the reader how he would willingly sacrifice his friendship for his own good.
Assef's admiration of Adolf Hitler gives us extra information about how the ruling of Pashtun class might view the Hazara people as the Nazi's views the Jewish people. It also is an insight to the extreme character of this bully who Amir refers to as a 'sociopath'. He is representative of the violent and uncaring and self-destructive country which Afghanistan is becoming at this time. The connotations of this reference enable the author to get across a lot of contextual information in just a few words.
Baba displays his love for Hassan by repairing his cleft lip which causes a strong jealous response from Amir. It's symbolic of healing but is eclipsed by Amir stating that Hassan's smile will be one of his last. This statement foreshadows future events and gives the reader a clue to the fact that the story is about to take a dark turn.