None other than webstress Megan McArdle told you so ages ago – now Newsweek money sage Robert Samuelson waxes on the fate of the all-mighty US dollar.

And it might not be pretty.

If you want to scare yourself, contemplate the following. The dollar begins to fall. That is, its value slips relative to other currencies. Foreigners with massive investments in U.S. stocks and bonds begin to sell their holdings. They fear currency losses on their American investments because a depreciated dollar would fetch less of their own money. The selling then feeds on itself. The stock market swoons. American consumer confidence withers. The recession resumes and spreads to the rest of the world through lower U.S. imports. Wham!

Is this horror story likely? Probably not. Is it possible? Well, yes.

Megan, feel free to say “I told you so” from that island paradise where you’re vacationing.

NOTE: The headline to this story comes from an Econ 101 lecture given by Professor Johnson at the University of Missouri-Columbia, way back in the fall of 1988. He was a fine teacher, and one not afraid to use a little bombast to make an important point.