The Chinese are getting nervous. They are sweating over the possibility that the US dollar could get wiped out.
Tough crap, China. You practice the age-old craft of mercantilism by forcing your currency down so that you can flood our retailers with cheap goods at the expense of US workers. Now you're sitting on an enormous pile of US dollars that you fear could be worthless.
Who's dumber? The country that produced a lot of paper and exchanged it for manufactured goods, or the country that willingly accepted (and encouraged production of) that paper? Which country is more screwed?