We live in uncertain times. Individuals of all political stripes can at least agree on that.

Yet uncertainty is the friend of the smart investor. Without it, the stock market would slowly move upward -- probably at the rate of inflation.

And that would be awful.

No, really awful
Does that sound contrary? Maybe it is. But remember that Warren Buffett has said it is always tougher to outshine the broader market in a strong year. When Buffett was leading his general partnership, for example, one of his best years was 1960, when he beat the market by 29 percentage points. He was up 22.8%, while the market was down 6.2%. See, Buffett made serious money by buying into stocks that others were afraid to.

All of this is to say that today is a very good time to be investing in foreign stocks. Whether it's the omnipresent terrorist and nuclear threats, rising energy demand, volatile energy prices, a weakening dollar, or a lack of understanding of foreign economies, American investors are not nearly as invested in foreign equities as they need to be.

And if you don't think the foreign economies are booming, it might pay to heed a few of the lessons taught by New York Times columnist Thomas Friedman in his recent book, The World Is Flat.

Signs of a flat world
For Friedman, "intellectual capital now exists everywhere and can be delivered anywhere." And this is a dynamic era. The Internet, for one, has broken down many artificial barriers inhibiting innovation or investment.

In India, Wipro (NYSE:WIT) and Infosys are doing backroom work for many of the world's largest corporations, including General Electric (NYSE:GE), American Express (NYSE:AXP), United Technologies (NYSE:UTX), and Schlumberger (NYSE:SLB).

In China, Ohmae & Associates is helping Japanese firms outsource data-entry work despite a century of ill will between the two countries. And Microsoft (NASDAQ:MSFT) and Dell (NASDAQ:DELL) employ customer-service representatives in India who not only speak English, but can speak it with various American accents. Seriously.

Investors and the flat world
Simply put, globalization is destabilizing centuries-old business practices, and the foreign companies making this happen are the next great growth frontier. As an investor, you can't ignore this trend. It is absolutely crucial to add foreign companies to your portfolio as soon as possible.

Unfortunately, the world is uncertain, and it can be difficult for Americans to determine which countries and which companies are deserving of their investment dollars. That's why we offer Motley Fool Global Gains, our new investing service that focuses exclusively on foreign equities. The service is led by Fool senior analyst Bill Mann, whose experiences living, working, and investing abroad will help you make money from a flattening world. To try Global Gains free for a month and see Bill and team's inaugural picks, please click here.

Kristin Graham updated this article, originally written by Tim Hanson and published Oct. 26, 2006, and does not own shares of any company mentioned. Microsoft, Dell, and American Express are Motley Fool Inside Value recommendations. The Fool owns shares of American Express. The Fool has a disclosure policy.