When you think about the government’s exploding debt burden, you probably don’t focus on interest payments.

But those payments will likely total $4.8 trillion over the next 10 years, amounting to more than half the government’s $9 trillion in debt.

Interest rates are near zero now, thanks to the Federal Reserve’s massive monetary stimulus. But at some point the Fed will have to reverse that easing.

"When interest rates rise, even a small amount, the interest payments go up a lot because of the size of the debt," Charles Konigsberg, chief budget counsel of the Concord Coalition, told CNNMoney.com.

The $4.8 trillion interest-payment estimate made by the Congressional Budget Office assumes some interest rate appreciation. But if rates rise higher than its estimates, the dollar total will be higher.

The Obama administration has pledged to cut the budget deficit to 3 percent of GDP, down from 10 percent last year.

But that goal may be more fantasy than reality.

"Even under the president's (2010) budget as evaluated by the CBO, we do not get anywhere close to that," William Gale, a senior fellow at the Brookings Institution, told CNNMoney.com.

Mike Larson, an interest rate analyst at Weiss Research, puts it like this in Money and Markets newsletter: “We’re in hock as a nation like never before. Neither the administration nor Congress has any plan to change that fact. And both the actual and hidden costs of our debt are rising every day.”