Interest expense for the fiscal year of 2012 was actually 360 billion. And interest rates are at record lows, lets just say that interest rates jump back to ave

Interest expense for the fiscal year of 2012 was actually 360 billion. And interest rates are at record lows, lets just say that interest rates jump back to average levels, then your looking at more than doubling that amount over the next 10 years as the debt gets refinanced and more debt gets added. Hardly sustainable. And the Fed is deliberately keeping interest rates at a ridiculously low level, so that the debt burden can be kept low, but we can't have that forever and things aren't looking too good in the near future.