Salon.com has an interesting article by Prof. Alfred McCoy at University of Wisconsin-Madison. Titled, How America will collapse (by 2025), Prof. McCoy asserts the the decline of American empire has begun. While I largely agree that America is on inevitable decline, it is rather difficult to ascertain that decline will be as swift as it is predicted. Among many variables, one problem with projected rise of China as a major super power, discounts the fact that Chinese leadership will face equally challenging times. As the middle class population increases with significant economic power, it is likely that there will be pressure for more open and democratic norms in China. A failure to manage the political aspiration could lead China off the track from becoming the single most powerful country in the world. In addition, any weakening of Chinese State is definitely likely to invite simmering discontent among Tibetans and Ughuirs to the fore and create a huge challenge for Chinese authorities.
The American decline definitely is in progress but decline is most likely be replaced by a more than one country and we might see multi-power world, with China, India, Russia, Brazil, US, and Europe having considerable power within each block.
The alliance of these nations and regions is most likely tilt the favor in one or the other way in a broader global domination chess game.
The most scarier perspective, however, is the rise of multinational corporations as a super power. Given that they actually control or have significant influence over all current States and the rising disparity between rich and poor around the world, their control is in place. Now, the question is whether this indirect control will lead into more direct control, through influence over military and technology.