> The government has no power to prop up the value of the USD if the world decides it's worthless.
I don't see "the world" deciding USD is worthless anytime soon: people in third world nations keep pristine US cash in their closets as a store of value; a lot of international trade uses dollars as a common currency; etc. If "the world" decides that dollars are worthless, that will be the least of my problems while I'm cowering in the bomb shelter I don't have.
It might be different if Middle East decides it prefers to be paid in yuans not usd. Of course you can then rain a bit more democracy on them but then again China might take offence.
