Americans are hideously lazy. They take prosperity for granted and don't appreciate that their prosperity was paid for with the blood of their predecessors. They are proud of their economic, cultural, and temporal ignorance.
The USA has been the dominant power on Earth for a very SHORT time. History has shown that world powers seldom stay on top for long. The Roman Empire was the exception... not the rule.
I only hope the system stays intact for another 60 years or so, so that I'll be gone when everything comes crashing down and only my kids have to deal with it. :-)