According to this NYT article (http://www.nytimes.com/2009/11/23/business/23rates.html), debt service was $202B in 2009. It is projected to go to $700B in 2019.

To put that in perspective, $500B more than covers what we spend on education, energy, homeland security and the wars in Iraq and Afghanistan.

Of course, this assumes that our interest rates stay the same. I don't see how this is possible as our debt/GDP rises. I fear we are seriously choking ourselves.