It's the interest.
In the wake of the financial crisis and recession, Moody's Investors Service has brought new transparency to its sovereign ratings analysis — so much so that 2018 lights up as the year the U.S. could be in line for a downgrade if Congressional Budget Office projections hold.
The key data point in Moody's view is the size of federal interest payments on the public debt as a percentage of tax revenue. For the U.S., debt service of 18%-20% of federal revenue is the outer limit of AAA-territory, Moody's managing director Pierre Cailleteau confirmed in an e-mail.
Under the Obama budget, interest would top 18% of revenue in 2018 and 20% in 2020, CBO projects.
But under more adverse scenarios than the CBO considered, including higher interest rates, Moody's projects that debt service could hit 22.4% of revenue by 2013.Chaos is the name of Obama's game.