Is America in decline, or about ready to move to the next level?

Every contrarian bone I have in my body tells me that America is about ready to enter a new era of worldwide expansion on a grand scale, considerably necessitated by self-interest and quite possibly as a pre-requisite to behind the scenes political and diplomatic demand from those nations who fear current rising great powers who do not aspire to their cultural goals and ideals.

However, as noted in many publications, newscasts, university lectures, etc., America seems to be riding the path to insignificance that has plagued many other regional and world powers in the past, including the Greeks, Romans, Chinese (who are supposedly ready to take over), Byzantinians, and the English/British, to name a few.

Notwithstanding the negative 'press' concerning Americas certain decline, my thinking is inspired by many sources, including investment strategy used by many of the most successful money moguls on the planet. An example of this ideology can be illustrated by paraphrasing the investment doctrine of the great Warren Buffet, the worlds premier buyer and seller of everything, as he elaborates on the above mentioned contrarian ideology by stating, 'You pay a very high price in the stock market for a cheery consensus', and this would tell me that the opposite must also be true in that the current global morosity concerning America is evidence that it is ready to soar. 

Your thoughts would be very much appreciated, Anson
References:

http://www.investopedia.com/articles/financial-theory/08/contrarian-investing.asp

The Modern Scholar: The Tiber and the Potomac: Rome, America, and Empires of Trust
Thomas F. Madden

http://www.economist.com/blogs/freeexchange/2010/01/roots_american_dominance

http://www.guardian.co.uk/commentisfree/2008/sep/28/usforeignpolicy.useconomicgrowth

http://blogs.telegraph.co.uk/news/alexspillius/9363517/Obama_signals_the_end_of_American_dominance/