The dollar is the global reserve currency...I remember in the worst years for the US economy 2008/09, the Dollar went up, because the rest of the world fled to it to combat their own inflation.
America's "enemies" are no expcetion to the above. China would be a big loser if the dollar crashed because its exports would become uncompetitive. China is propping UP the dolalr and will continue to do so, buying it for their resevres if it falls too low. This is why the Republicans call them "currency manipulators" The same is true to a lesser extent of all the emerging economies, especially the BRIC, but even "enemies" like Chavez and Ahmadinejad.
Some extremists - libertarians and marxists - are obsessed with predicting the collapse of welfare capitalism. But WHEN? they have been predicting this for decades, and it never happens. There are crises, but the system recovers stronger. Debt does not NEED to be payed off all together, debt and growth fuel each other, provided it is well invested.
An example, not many businesses have grown without contracting debt. In Business Studies and Finance they call it LEVERAGE and it is assumed to be a necessarry precondition of growth (with the difference that companies and issue equity and countries cannot).
A country is more like a business than a household.
The Dollar will survive for the forseeable future, welfare capitalism will survive, LCD TV and 4x4 for everyone.
One distant day it will end, one day it will die, like all people, all things, like the universe itself. But we don't need Friedrich Hayek or Karl Marx to tell us this. and catastrophist solutions would only make our lives much worse, not better.