It usually all boils down to money. The link has government bond rates for various industrialized countries. Its interesting that Wall Street deems western countries to be three times as risky as Japan. My theory is that the fact that the Japanese have shown a propensity to disect live prisoners has something to do with the stability of their financial systems in the eyes of analysts. Lending money to the US is riskier than lending money to Europeans. Note how yields are going up and to the right for everybody since 2005.