We are far apart, but I would hazard a guess that the Objectivism of Ayn Rand is more a minority viewpoint than my Christianity (which is not the moralistic legalism of many Americans). Maybe I am wrong. Both are views are minority viewpoints today, though on the topic of right and wrong I think most people would agree with my thinking because of the past influence of Christianity in Western World. I don't think objective selfishness will bring about world peace. I think altruism could if we could not be selfish, but selfishness is part of our nature and so it is a nonstarter for us. As I see it, the problem is I desire something; I then rationalize why I should have it; and then I take it. That does not bring about peace. That rationalization is flawed because I can not guarantee that my reason will be impartial and perfect. I am not certain if it ever can be.
Note from the book you recommended, I made an assumption that you follow the teachings of Ayn Rand. Correct me if I am wrong.