What caused the United States to lose its AAA rating for the first time in 94 years, a rating that withstood two world wars, the Great Depression and (most of) the Great Recession, and a costly military buildup that bankrupted and demolished our Cold War foe, the Soviet Union, without a direct shot fired? Was it the dastardly Tea Party, with its demands for fiscal sanity and a solution to an oncoming tsunami of entitlement liabilities? According to the man who rates sovereign debt for the agency that downgraded the US, not really: