Great American companies have long known something that some investors are just realizing -- the benefits of international diversification.

The world is yours
Consider that Coca-Cola (NYSE:KO) opened its first factory outside the United States in 1906, followed by Procter & Gamble (NYSE:PG) in 1915, and Johnson & Johnson (NYSE:JNJ) in 1919. All three international ventures started small, but the reasoning for them was simple and clear:

  1. Tap new markets in order to
  2. Fuel growth and
  3. Diversify revenue streams

The decision to take any company international is risky -- added currency and political risks, as well as cultural differences, are inherent obstacles for any international business. But these companies understood that the benefits far outweighed the risks, and, well, I'll let the results speak for themselves.

Last year, the three companies generated more than $70 billion in combined revenue from international operations. What's more, Coca-Cola and Procter & Gamble consistently generate more than half of their business in foreign markets. Needless to say, without the success of their international operations, these companies wouldn't be the megacaps they are today.

In the past decade or so, "new economy" American companies such as Autodesk (NASDAQ:ADSK), (NASDAQ:AMZN), Electronic Arts (NASDAQ:ERTS), and Yahoo! (NASDAQ:YHOO) have embarked on their own international projects, and succeeded so far. Today, all four receive more than 30% of their revenues from outside the United States.

A matter of dollars and pence
Generating revenues from outside the United States is especially important for American corporations in this declining dollar environment. Just five years ago, one euro cost $0.90; today, that same euro costs roughly $1.33.

If an American corporation generated some of its revenues in euros during this period, it not only reduced its overall currency risk, but actually augmented its profits when converting the stronger euros into weaker dollars.

The inverse situation would occur if the dollar becomes stronger relative to other currencies. In addition, a stronger dollar would provide U.S. multinationals with opportunities to purchase foreign assets on the cheap.

Take a page, or two
Like the aforementioned multinational companies, we as individual investors should also be looking overseas to increase our portfolio's growth while reducing risk through diversification.

Buying shares in foreign stocks in the form of American Depositary Receipts (ADRs) is a great way for us to do just that. That's also why we recently launched our newest service, Motley Fool Global Gains -- to help you navigate the international waters to find the best foreign stocks for your portfolio.

If you're interested in learning more about international investing and receiving two new international stock ideas each month, click here for a 30-day free trial of Global Gains. You'll be glad you did.

Todd Wenning does not own shares of any company mentioned in this article. Electronic Arts and Yahoo! are Motley Fool Stock Advisor picks. Coca-Cola is an Inside Value selection. Johnson & Johnson is an Income Investor recommendation. The Fool is investors writing for investors.