yeah but the US doesn't really control the value of their own dollar. the value of the dollar is set by outside forces. supply and demand plays a factor, but so does sentiment toward the dollar by those outside the US.
china is dependent on the US when it comes to exporting their goods. and while the demand for those goods would decrease if they decided to nuke the global economy, it would screw the united states even more.
the US just writes large IOUs and defers the decision for a later generation. at some point, someone is going to show up at the collection window and ask for their money. china can merely threaten to do it and the US will fall in line.
