= new reply since forum marked as read
Europe is as big a market for China as the US is. Problem is, if the US dollar tanks, their exports plummet, too. (They export a lot to us.) It is possible that the Euro could become a temporary reserve currency ( 
NOT!!!!! ) but even if that were to happen, it would take quite a while. China would suffer an instant 20% loss to their exports. China lost 20 million jobs in 2008 because of far milder losses; a sudden 20% drop in exports, for China, equals economic evisceration.
China is trying to slowly build other export markets, like in Africa and South America, before they dump the US dollar. But even before the dollar gets dumped, the rise of other markets will mean the end of cheap foreign labor, since workers in those markets will want higher wages. Plus, China's own workers are demanding higher wages. That will kill their competitive advantage, and while that will damage their ability to export to S. America and Africa, the ongoing devaluation of the US dollar will multiply China's wage growth into an absolute double whammy against importing Chinese goods here.
In short: China doesn't want to do jack shit about America's debt to them. What they want to do is slow down the inevitable collapse of globalism as workers in other offshore outsourcing-haven nations demand higher wages, and their nations' currencies rise - which is a double-whammy against the whole of globalism.
