How does Amir feel during the confrontation with the Russian soldiers while they were being smuggled in the truck?

Amir an Baba are being smuggled out of Afghanistan. The truck was supposed to have no trouble crossing through the Russian-Afghani checkpoints because of the driver, Karim's connections. At a checkpoint, the Afghani soldiers would have let the truck pass without issue, but one Russian soldier demanded a half hour with one of the refugees, a married woman. To Amir's dismay, Baba defended the woman, telling the Russian soldier that he had no shame and that he would "take a thousand bullets before [he] let this indecency take place." Amir felt ashamed that while Baba would give his life to save someone, he did nothing to save Hassan.