Look at how many US bonds they hold. China has been drawing down their holdings since the inflation bubble. At the beginning of quantitative easing, it was pointed out furiously by other countries that Bernankes QE would influence countries tied to the US dollar...
Here is an article from a third source so everyone can swallow it better but if you'd followed the news, you'd have known long ago:
QUOTE: "Likewise, if U.S. political paralysis provokes even a brief debt default this summer, the dollar could slide and global interest rates may spike because U.S. bonds are the benchmark against which other issuers are measured.
But if the U.S. economy takes a sharp turn for the worse, the U.S. Federal Reserve may see no choice but to pump in more money. Asian emerging markets have complained bitterly that the Fed's latest round of bond purchases spawned asset price inflation elsewhere."
He does have the power. He does not explain it that way becuase if the general population understood, it would thoroughly destroy the markets and possibly cause panic on a monumental scale.