The truth is that the US government gives a lower percentage of our GDP to international charity efforts than the other members of the industrial seven. And, as much as I want to blame Bush for this, it is something that has always been the case, and not because we are stingy.
Unlike those other countries, Americans give a significant amount of foreign aid through private organizations. In other countries, the citizens give through their governments. Recent numbers I heard on a CNN report suggest that our giving is on par with the other countries, if not sometimes exceeding them, because of the emphasis on private giving here.