No doubt this is somewhat political, but they do it because they can:
Dagong Global Credit Rating Co used its first foray into sovereign debt to paint a revolutionary picture of creditworthiness around the world, giving much greater weight to "wealth creating capacity" and foreign reserves than Fitch, Standard & Poor’s, or Moody’s.
The US falls to AA, while Britain and France slither down to AA-. Belgium, Spain, Italy are ranked at A- along with Malaysia.
Dominique Strauss-Kahn, chief of the International Monetary Fund, agreed on Monday that the rising East is a transforming global force. "Asia’s time has come," he said.
Not sure what effect this will have on interest rates etc., but in my understanding, it can only bring upward pressure to bear.