An
interesting article from slate describing the collapse of the American Empire and how it is happening faster than anyone expected.
The author also describes 4 independent scenarios of what it might look like.
Economic Decline
Oil Shock
Military Misadventure
WWIII (Without a single human casualty).
While my thoughts are not as dire as the authors, it would seem that the US has significant structural obstacles in its path and is lacking the political will to deal with them effectively.
[Edit - Another
NYT opinion piece imagining what the Chinese embassy cables might look like if wikileaks were to release them. Sheds a lot of insight on the structural issues Americans are avoiding]