Ishmael ends his story not with his safe arrival in America, but with a little tale he heard as a boy: You are a hunter and you are about to shoot a monkey. Before you can pull the trigger, the monkey tells you that if you kill him your mother will die. If you don't kill him, your father will die. What do you do?
Ishmael finishes by telling us his solution:
When I was seven I had an answer to this question that made sense to me. I never discussed it with anyone, though, for fear of how my mother would feel. I concluded to myself that if I were the hunter, I would shoot the monkey so that it would no longer have the chance to put other hunters in the same predicament. (21.57)
This is a pretty amazing answer for a little kid. It also shows Ishmael's state of mind at the end of the book. Either choice he makes, a person he loves will die. But Ishmael decides that the greater good is served by taking out the one forcing him to make a seriously impossible choice. Sorry, monkey. This is kind of your own fault.
If you think about the monkey being the power players in the war in Sierra Leone, you can understand Ishmael's thinking. In the end, the monkey—the government—isn't really giving you a choice at all. Ishmael is willing to do the thing that stops the cycle of violence.