I stated in the comments that "I always knew the 'American century' would come to an end, but Bush is doing all he can to accelerate the process" and was asked for details. Here is how I see it.
The decline of the American century isn't just one or two things, it is how all the pieces play together. The deficit, the declining dollar, the weakest military since Vietnam1, the anti-Americanism, the decline of Pax Americana, the weakening of international law, the promotion of might makes right foreign policy, torture, the increased distribution of wealth to the rich and the largest corporations, and the increased difficulty of the world's brightest to study in the US all play a part.
Because of the declining dollar, low interest rates and our massive debt America is a relatively poor place to invest compared to other countries, just as we are directing more money to those Americans who can most easily invest elsewhere. Combine this with the huge decline of foreign students studying in the US and we face a world where US entrepreneurship declines while entrepreneurship in the outside world climbs to new heights, largely funded by US dollars.
Note this isn't the normal cycle of average Americans buying cheap stuff from overseas spawning growth in those nations and ours, this is a cycle of investment and return that ignores the bulk of America. Trade deficits don't bother me all that much. Other nations getting richer don't bother me at all; we all benefit from that. This is something entirely different, mega-rich international corporations controlled by a new international aristocratic class that answers to no nation.
As the EU, China and others (India?) become dominate players on the global scene, other countries have more options of whom they'd like to emulate and whom they'll go for their strongest aliances. If they go to the EU instead of the US, then our power decreases, but I don't mind the world outcome too much. If they go to China, it's a whole other story. I tend to believe China can't increase their push for capitalism and economic power while maintaining their totalitarian regime, but I don't really know that. But certainly they can maintain the balance for a while and woe be the world that choses to emulate that system.
For the first time in our country's history, America is no longer the place others look up to, no longer where the world sends it's brightest to learn, no longer the only obvious choice of where to immigrate, no longer the one country you want to imitate, no longer the beacon of hope for the world, no longer the one country you want to be when you grow up.
As I said, I knew the 'American century' would come to an end. While I'm a great believer in Pax Americana and think we've been very good to the world (on a whole, warts and all) I don't think the end needs to be all that bad; we have great power now to influence the new, emerging world. But right now, at that point of influence we are steering the world away from international law and towards a world of might makes right. How ironic that we push the might makes right doctrine so strongly just as our might starts to decline. And how horrible.
Now, as I've just stated these points it sounds like I believe the world is about to blow up or go to hell or enter the worst era of lawlessness we've ever seen. I don't believe this. There are many, many good things are happening in the world as well and these events are not the only actors. But these are the paths I believe Bush are leading us down. While we could be building towards a much better world, it is as if we desire the worst.
Hopefully, I'm just plain wrong. Or perhaps I've got the trends right, but some of the trends Bush actually intended are also there; certainly the pro-democracy movement in the Middle East is heartwarming. Perhaps once some grownup cleans up after all of Bush's messes what remains of his presidency will be positive; the bad cop that got the bad guy talking; the kick in the rear that got everyone moving; the example of how bad America can be that will help the world appreciate how good we normally are. I'm an optimist by nature, I can't really help myself, so I'm beginning to believe we may see some good from all this yet. I sure hope so.
1In terms of our ability to respond to any emergency, the military is extremely weak right now because they are deployed, but it is more than that; the perception of power has weakened as well.