How does the usa rule the world both military and economically?
Interestingly, America's global dominance is generally not thought to be restricted by the lack of superiority regarding its educational system nor lessened by the noticably unimpressive cerebral capacity of the average member. Your rather interesting question would certainly not noticeably challenge such a conclusion anyway.
America does business with countries which it considers OK by making sure the elites from those countries remain rich and powerful and secure.
And it threatens force or uses force against countries it doesn't like, destroying the elite's lifestyle and saftey.
Basically... buy the hamburger, blue jeans, baseball cap and funny talking mouse or we'll bomb you.
Foriegn countries let American corporations make money from them by radically changing their culture to a low-brow consumer culture. Or other American corporations that make military equipment will profit from the destruction of their infrastructure.