Greenspan wrote in the financial times today that the US is pursuing a policy of devaluation of the US dollar, which has pushed up the exchange rate of other currencies in the world.

China is also lowering its currency. The upward pressure on other countries' currencies may lead to a general rise in trade protectionism.

After the second round of quantitative easing monetary policy launched by the Federal Reserve in November 3rd, many officials from Germany and Russia openly expressed their dissatisfaction with the United States' arbitrary "money throwing".

Jean Claude Juncker, the chairman of the euro group, said on the eve of the summit of the group of twenty that the dollar was undervalued and that the Fed's stimulus policy could bring risks to the whole world.

Agence France-Presse reported that the Europeans were worried that the injection of so much liquidity into the US economy would reduce the value of the US dollar, thereby devaluing the US dollar against the euro.

In November 9th, Nicolas Eyzaguirre, the head of the International Monetary Fund, said in November 9th that the US Federal Reserve could launch the third round of quantitative easing policy because the US economy has not recovered for a long time.

He said: "although we believe that the current economic situation in the United States is not enough to fall into a double dip recession, economic growth may remain at a very slow level, which will prompt the fed to take further unconventional measures."