The current US National Debt is over $14.8 Trillion. Much of this debt is owed to U.S. residents. Among the external creditors, China is the largest holder of U.S. debt.

The U.S. spends a large portion of its budget each year in the form of interest payments  to service the huge debt load. The following chart shows that the U.S. spent $414.0 billion on interest payments in 2010 which is higher than the amounts spent on many Federal departments. One can argue that the high interest expense deprives the U.S. from funding education, innovation , science and technology, healthcare, infrastructure and other important programs.

Source: The Heritage Foundation