A horse cannot gain weight if not fed with extra fodder during the night; a man cannot become wealthy without earnings apart from his regular salaries.
-- Chinese proverb

That Chinese proverb makes a strong case for investing period, but there's more to it.

If you can't become wealthy without earnings apart from your regular salaries, I'd posit that in today's world, an American investor can't earn mind-blowing returns without extra fodder from some of the world's fast-growing economies.

A Chinese proverb, an American investor ...
That's not a knock on our economy -- it's still the largest and most dynamic in the world. But it's a slow grower, and that's a fact of life now.

Gearing your portfolio toward global markets certainly paid off in spades in recent years; the broad-based iShares MSCI EAFE Index (NYSE: EFA) returned more than 110% over the past five years, well above the 34% returns the S&P 500-tracking SPDRs (AMEX: SPY) offered. Had you weighted your investments toward emerging market winners -- even large and well-known stocks like PetroChina (NYSE: PTR) and Brazilian miner Vale (NYSE: RIO) -- by now you'd be bragging about a number of multibaggers in your portfolio.

Indeed, emerging markets represent some of the world's greatest values, but given the current unease in international markets thanks to a U.S.-based credit crunch, as well as the inherent political, economic, and currency risks that go along with emerging-market investing, a more conservative approach to international markets has its merits these days. And I believe there's a way to earn emerging-markets returns in a more conservative manner.

How so, then?
See, you can get emerging-market returns by selecting the right fast-growing developed market.

Playing it safe doesn't mean cutting off all your upside potential, either. South Korean steel producer and recent four-bagger Posco (NYSE: PKX) hails from a developed yet fast-growing economy. Actually, there are a handful of developed markets that pack the growth punch of some emerging markets.

Singapore is one such developed market. The Singapore market's 190% rise over the past five years rivals the stellar performance of the emerging markets I mentioned above. Singapore also has a number of impressive economic underpinnings that should translate into stable stock market gains for years to come.

The ascent of Singapore
Singapore has come a long way in the four decades since breaking from the Malaysian Federation to become its own country. What has followed is economic growth that has catapulted its citizens to among the world's wealthiest: per-capita income is just under $50,000, nearly $3,000 higher than in the United States.

Singapore rivals Taiwan as one of Southeast Asia's foremost technology hubs, with an emphasis on R&D, high-tech electronics manufacturing, and a thriving biomedical community. Contract electronic manufacturer Flextronics (Nasdaq: FLEX) calls Singapore home given its healthy mix of high-tech know-how and production capacity, while foreign firms, such as California-based Affymetrix (Nasdaq: AFFX), are moving manufacturing plants to Singapore for a competitive edge.

Singapore's open economy, world-leading education system, and acceptance of immigration as a way to keep growth humming and wage pressures at bay have contributed to high-single-digit economic growth in recent years. While our own economy -- not to mention the economies of many European nations -- is struggling, the Economic Intelligence Unit forecasts that Singapore will continue to expand real GDP around 5% and even awards the nation one of the three highest business environment ratings on the planet.

The Foolish final word
Broad, passive investment exposure to Singapore can be obtained by the iShares MSCI Singapore Index ETF, while the closed-end Singapore Fund offers another diversified approach. Stock jocks will find Singapore's national champions -- including United Overseas Bank and industrial transport giant Cosco -- trading on the Pink Sheets.

Our Motley Fool Global Gains team was in Singapore earlier this month to ferret out lucrative investment ideas. You can read our team's notes from their trip to Singapore, and you can see their best investment ideas from the rest of the trip (which included stops in China, Vietnam, and Indonesia as well) with a free 30-day trial. You'll also get our top five international stocks for new money. Just click here to get started.

Fool contributor Ryan Fuhrmann has no financial interest in any company mentioned. Posco is a Motley Fool Income Investor recommendation. Affymetrix is a Rule Breakers selection. The Fool owns shares of SPDRs and has an ironclad disclosure policy.