The list of biggest Gross National product in the world goes like this:
1. European Union
2. United States
3. People's Republic of China
However, the three lists at wikipedia are the IMF, the World Bank, and the CIA factbook
and even though California is not on this list because it is a part of the U.S. it is widely known to be number 8 GDP in the world.
IF the 8th largest GDP on earth suddenly goes bankrupt, I think the affect not only upon the US but on the world would be much more serious than GM or Chrysler going bankrupt. IN fact, it could trigger about 46 other states to go bankrupt as well in the next 5 years. However, if Obama bails out California he might not be able to bail out the other 46 states set to bankrupt in the next 5 years. This one fact might be the undoing of the U.S. within 10 years.
The international repercussions of a California bankruptcy are impossible to calculate at present.