China’s central bank on Monday proposed replacing the US dollar as the international reserve currency with a new global system controlled by the International Monetary Fund.
“This is a clear sign that China, as the largest holder of US dollar financial assets, is concerned about the potential inflationary risk of the US Federal Reserve printing money,” said Qu Hongbin, chief China economist for HSBC.
This is basically a threat - inflate (read default) and you'll loose your influence.