I agree with geostrategist Zbigniew Brzezinski, who was Jimmy Carters National Security Advisor and is now foreign policy advisor for Obama. He says that the USA are the only superpower, and actually the first real superpower in history. He also says that the USA will probably be the last superpower, and they will lose that status in a few decades.
I can really recommend reading his book "The grand chessboard". It not only discusses the various possible "superpowers" (and why they aren't and never will be), it also discusses the geostrategic importance of many countries. He calls France, Germany, Russia, China and India "geostrategic main actors", while Ukraine, Aserbaidschan, South korea, Turkey and Iran are what he calls "geopolitical linchpins" (actually those are just 1:1 translations from my book, in the english original he probably uses a slightly different term). He also discusses why the U.K. is getting more and more irrelevant. It was one of the most interesting books I've ever read, as was Huntington's "The Clash of Civilizations".
