According to the National Association of Investors, just one in three Americans feels "comfortable" investing in foreign stocks or bonds.

And that, my friend, spells trouble
If this thinking continues, hardworking Americans like us could be headed for some woeful underperformance, if not disaster. Or so says "the Smartest Man in Europe."

The smartest who in what? Well, that's what Byron Wein calls him. According to Wein, this fellow earned his title by identifying trends that would have major impacts on global financial markets.

This guy even called the collapse of communism and the dismantling of the Berlin Wall. And yes, he warned us to start looking abroad before the recent bull market in foreign stocks.

You think I've lost my mind, don't you?
In my defense, Byron Wein spent years as a top equity analyst at Morgan Stanley. So I believe him. As for his mystery man ... who cares? He seems to be on to something.

In 2005, stock markets in countries as diverse as Egypt, Russia, Turkey, South Korea, and Austria all gained 50% or more -- dwarfing U.S. stocks. I'm starting to sense a long-term trend. And no, we haven't missed the boat.

In fact, when Wein last crossed the Atlantic to consult with his clandestine friend, he was more adamant than ever that we start moving our investments overseas. For what it's worth, I'm taking him up on it.

"Global is definitely the way to go"
If you're not up for trusting your future to some "mystery man," how about a Wharton professor? When Jeremy Siegel met with us here at Fool HQ, those were his exact words. More important, he said we should hold as much as 40% of our portfolios in foreign stocks.

I wish I'd listened. Last year, while the $58 billion Fidelity Magellan fund rode positions in General Electric (NYSE:GE), American International Group (NYSE:AIG), and Google (NASDAQ:GOOG) to 4.6% returns, international stock funds routinely delivered 20%-plus gains. Meanwhile, American institutions such as Wal-Mart (NYSE:WMT) and Home Depot (NYSE:HD) struggled to eke out single-digit gains, and mighty Dell (NYSE:DELL) didn't even manage that. And that's to say nothing of the whooping Toyota is putting on General Motors (NYSE:GM).

Born on the fourth of July
I assure you, I'm not some doomsayer prophesizing the collapse of the West and the rise of "Chindia." I have too much faith in America ... and too much invested in the U.S. markets.

But more than half the capitalization of all public companies already resides overseas. And just last year, investors poured $53 million into foreign large-company funds, up 32% from the year before. And I'm one of them.

I settled for the iShares EAFE Index. Because I confess: I'm too chicken to invest overseas stocks on my own. But I have a mystery man, too -- a Bill Mann, to be specific. Bill is a globetrotter and an expert on global markets. I don't move without checking with Bill first.

Need help, too?
Fortunately, you don't have to cross the Atlantic, either. Bill recently launched a service called Global Gains to help you get invested overseas. Bill's a serious expert, so it's not cheap to join. But you can try the service free for 30 days and pay nothing.

Of course, you won't actually go broke if you don't invest overseas. But it could cost you some money. Why not take Bill up on his free trial offer, instead? To learn more, click here.

Fool contributor Paul Elliott owns shares of the iShares EAFE index, but no other company mentioned. Wal-Mart, Home Depot, and Dell are Motley Fool Inside Value picks. Dell is also a Stock Advisor recommendation. The Motley Fool has a disclosure policy.