From S&P:
Overview
We have affirmed our 'AAA/A-1+' sovereign credit rating on the United States of America.
The economy of the U.S. is flexible and highly diversified, the country's effective monetary policies have supported output growth while containing inflationary pressures, and a consistent global preference for the U.S. dollar over all other currencies gives the country unique external liquidity.
Because the U.S. has, relative to its 'AAA' peers, what we consider to be very large budget deficits and rising government indebtedness and the path to addressing these is not clear to us, we have revised our outlook on the long-term rating to negative from stable.
We believe there is a material risk that U.S. policymakers might not reach an agreement on how to address medium- and long-term budgetary challenges by 2013; if an agreement is not reached and meaningful implementation does not begin by then, this would in our view render the U.S. fiscal profile meaningfully weaker than that of peer 'AAA' sovereigns.
