I am not here to prove anything except to say that these are the basics. If a person did not know the basics, what kind of expert is he? The U.S is surrounded by oceans, I mean they are cut off from the African, European and Asian continents. Still the U.S is a Superpower. The oceans never blocked the U.S from becoming a superpower. Oceans are not restrictions but always gives a country the opportunity to go further without requiring anyones permission. As simple as that.