The U.S. Government did respond appropriately to the global financial crisis. The stimulus packages helped American people and American businesses. The bail out was also helpful. Important new regulations have now been adopted that may not otherwise have been. These include consumer and bank regulations. Now, both the U.S. and other countries around the world have growing or sustained economies.
I do not think the US responded appropriately to the global financial crisis because of two reasons. #1 I think America is selfish and #2, I don't even think American knows what it's doing financially. No Western country except Romania has more childhood poverty. Since America can't even keep it's own finances in order, it had no business interfering in global issues.