Paul Kennedy's Rise and Fall of the Great Powers is a fascinating book that I read a decade ago. Kennedy's central thesis is that in the long run, averages win. A few people can't stay on top of many, not for generations. A disproportionate fraction of the world's resources won't remain channeled through a single chokepoint --- Spain and Portugal in the 16th Century, England after that, then the USA, now the G-7 or whatever. Eventually, demographic factors triumph; incomes level out. Sure, that process can take quite a while, particularly if other countries handicap themselves with societal ignorance, shortsightedness, greed, or horrid misgovernment. Those who have wealth will try to use it to maintain their position. On long timescales, they can't succeed.