It was a good idea to get science and democracy from the ancient Greeks. It’s not such a good idea to get fiscal policy from the modern Greeks.

But that’s the way we’re headed.

Greece has a budget deficit of 13.6 percent. We’re not in that league — ours is only 10.6 percent, the highest level since 1945.

Greece has a public debt of 113 percent of GDP. We’re not there yet. But the 2009 Social Security and Medicare Trustees Reports show the combined unfunded liability of these two programs has reached nearly $107 trillion.

Under President Obama’s budget, debt held by the public would grow from $7.5 trillion (53 percent of GDP) at the end of 2009 to $20.3 trillion (90 percent of GDP) at the end of 2020. It could rise to 215 percent of GDP in 30 years. Welcome to Greece.

Here’s a graphic presentation of the official debt and real net liabilities of various countries, including the United States and Greece at the right. (From the Telegraph, apparently based on Jagadeesh Gokhale’s report.)

And here’s a Heritage Foundation chart on where the national debt is headed in the coming decade:

Paul Krugman wrote, “My prediction is that politicians will eventually be tempted to resolve the [fiscal] crisis the way irresponsible governments usually do: by printing money, both to pay current bills and to inflate away debt. And as that temptation becomes obvious, interest rates will soar.” Now he was writing in 2003, when a different president was in office, but he was also warning about the possibility of a ten-year deficit of $3 trillion. Presumably the same warnings apply to today’s much larger deficit projections. And he was absolutely right to fear that government would turn to inflation as a supposed solution.