Now, Gross National Debt as a percentage of GDP is over 100% and rising rapidly.

FORBES: Don't Cave GOP, This Time Deficits DO Matter

Those federal IOUs are rightly accounted for in federal finances not as assets but as part of the Gross Federal Debt, subject to the national debt limit.

FORBES: Social Security Personal Accounts Are A Path To Prosperity

The Italian government is not only reviewing its position on tax havens, the country is in dire need of spare tax revenues as one of the few European nations whose national debt has surged above 100% of gross domestic product.

FORBES: Tax Havens

But if health care is not reformed, Greenstein warned, the national debt could soar to 300 percent of the gross domestic product by 2050.

CNN: Obama pledges to cut deficit in half at fiscal summit

Based on the current rate of Federal spending, the national debt will be roughly 108 percent of our gross domestic product at the end of this fiscal year.

FORBES: Why The Obama Administration Is Wrong About The Credit Downgrade

He incurred the wrath of the International Monetary Fund and the financial community by unilaterally declaring a limit on debt repayment equal to 10% of the Gross National Product, isolating Peru from international financial markets.

CENTERFORSECURITYPOLICY: Peru: two terms of Garcia

Today, as an example, Brazil has total national debt of roughly thirty or so percent of its gross domestic product.

FORBES: Let Greece Implode

The Greek government is trying to reduce a national debt that stands at about 115% of its gross domestic output, and a public deficit that exceeds 13%.

BBC: Greece makes 'strong start' in cutting debt, IMF says

Eurobonds are corporate debt instruments issued outside the control of national tax authorities, and therefore pay interest gross.

ECONOMIST: Europe