The pomegranate could also be an allusion to the Greek myth of Persephone. Persephone is the daughter of Demeter, the harvest goddess. When Persephone is kidnapped by Hades, she is trapped in the underworld. Demeter causes all plant life to die, a mother too grief-stricken to do her job properly. Zeus, to save all plant life, intervenes and orders Hades to send her back to the land of the living, but because Persephone has eaten some pomegranate seeds in the underworld, she is compelled to spend as many months in the underworld as the number of seeds she has consumed. Some versions say she ate four pomegranate seeds, but in the version I remember from my childhood, she ate six. This is meant to explain our seasons, so many months of winter and so many months of summer. I don't know if the author had this ancient myth in mind, but it does seem apt in some ways, I think. Certainly, there is a level on which Afghanistan itself has become a dreadful underworld, taken over by evil, where nothing good can thrive, unlike the lush beauty of the boys' childhoods.