The Kite Runner- Chapters 9-10

In both chapters, Baba and Amir's relationship continually gets worse. I want to know what happened to Ali and Hassan when the war broke out? What was the car ride like to the bus station? I feel like the war is a little random and Im not sure when it happened and why? The bus and how they are trying to escape is a little confusing, and when Kamal dies, what exactly was wrong with him in the first place??? On page 120 there is italics writing that is important but Im not sure what the meaning is towards the themes of the book.