Oh, and the current budget projects that defense spending will decrease as a percentage of the federal budget. While the overall budget is slated to grow 75 percent during the next decade, defense is to grow just 17 percent. Only imminent and eternal peace would permit such low defense expenditures. The administration's health plans also will add a currently unfunded $1.5 trillion per decade.

Not only does continued, increased government borrowing ever more sap our economy but also, as the baby boomers retire, we will move from the recent statistic of four workers for each retiree to two workers for each retiree. That means a weaker economy, as this smaller work force will not produce enough to support all of government's costs -- even with massive and persistent tax increases. And if, as seems possible, sometime in the next decade the world resists lending our government sufficient money (because our economy will be too small to produce enough to pay the ever-growing interest on the debt), then we finally will be forced to make choices of what to buy and what to forgo. Maybe only subsidized pain pills rather than medical treatment for old people? Only 50 percent payment of Social Security benefits? Default on federal debt payments? Or what the Chinese already are worried about: monetizing the debt, leading to hyperinflation?

But the Roman Republic's experience hints at an even more profound danger. The political tasks flowing from the growing demands of the republic's empire were of a magnitude and type that could not be managed by its form of government. However, the Roman Republic was prepared neither to give up its growing empire nor to modify its government to deal with such challenges.

Similarly, for the United States today, we are not prepared to forgo what all this soon-to-be-unavailable deficit spending can buy us (health care, bank bailouts, defense spending, food stamps, etc.). Nor can our governments (and the publics who elect them) stop the spending.

In Rome, eventually a contradiction arose between Romans' concern for the tasks that needed to be performed and their concern for their form of government. The contradiction was resolved and the problems solved at the price of their republic: Came Gaius Julius Caesar.

Surely (presumably?), for the next decade, the United States will bungle onward with both our form of government and our deficit spending. But sometime soon after 2017, when Medicare's trust fund will begin to be depleted (or earlier, if the world stops buying our bonds), the shocking reality of being forced to do without borrowing will shape -- and probably misshape -- both our way of life and our form of governance.