This seems counter intuitive to me. We have a trade deficit, so our dollars are flowing out of the country to these other countries. There should be reserves of dollar denominated assets in those other countries. So I did a little research. They run about a $0.1T surplus with us but they import $2.5T of goods if their suppliers want to be paid in dollars, I see how this could be a problem. China would need to sell to other countries in dollars. Trade with someone like Russia (one of their bigger trading partners) has a hard time getting dollars on a good day would not help.