American in decline?

As it turns out, the constant drumbeat of "The Decline of American Power" is nothing new: http://www.realclearpolitics.com/articles/2007/08/declinism.html. The thing is, there is generally no way to tell if a decline is taking place until after it has already occurred. Given the standard of living in this country, the lines of people looking to move here (which aren't shrinking), etc., etc., I'm not of the opinion that this is a country in decline, much as some on the Left want that to be the case, or want the public to believe that that is the situation.............