Within the debate about the deficit, there is another debate about timing. If public debt does trigger a financial crisis, it won't be tomorrow. It won't be next year. It probably won't be in five years. So what is everybody doing running around screaming about the fierce urgency of VAT?

Here's Bruce Bartlett's answer:

What I expect is that when there is the inevitable flare-up in financial markets as bond prices crash, the dollar takes an unexpected dip, the price of oil shoots up or whatever that Congress and the White House will solemnly vow to cut the deficit because it will be the one thing that everyone will be able to agree upon that might help and at least won't hurt. Everyone will go out to Andrews Air Force Base and after weeks of intense negotiations announce that a deal has been struck to deal with the crisis.

Republicans will inevitably agree to some modest tax increases, Democrats will agree to trim Medicare and Medicaid, and both sides will promise that discretionary spending will be slashed.

A VAT could take a decade to set up and index until you're locked in at a long-term rate of 8 or 10 percent. But America's not very good at dealing with slow-moving crises, even with slow-moving solutions. We're much better at waiting until a crisis happens, acting quickly, and then putting together commissions to find out why nobody saw it coming.