The Dow Jones Industrials (^DJI 0.44%) have struggled so far in 2014, and emerging-market countries have received much of the blame for stock market volatility around the world. Yet when you take a closer look at the large emerging markets of Brazil, Russia, India, and China -- also known as the BRIC countries -- you'll find that they've been under pressure for a lot longer than just the past month and a half. Let's take a closer look at the BRIC countries and why they've underperformed the Dow.

What's behind the BRICs' declines?
Investors are beginning to panic over very mild declines in the Dow this year, even though the U.S. market hasn't seen a substantial correction in years. Yet stock markets for the BRIC countries haven't just underperformed the Dow since 2011 -- they've actually fallen over that time, which comes as a surprise to many investors who think of the past five years as an almost uninterrupted bull market.

As tempting as it is to lump emerging-market nations into one class, the fact is that each country has its own specific dynamics that give them different risk profiles. Even among the BRIC nations, you can see wide variations in stock market performance.

Banking on resources
For example, among the BRIC countries, Russia and Brazil have traditionally been a lot more dependent on natural resources to fuel their respective economies. Russia has a wealth of oil and natural gas that it uses not only domestically but also as a key export to energy-hungry nations in Europe. Even though world energy prices have remained reasonably high, the energy boom in the U.S. has greatly reduced its need for imported oil, and that has implications for Russia's economy. Russia also has mineral wealth in metals, but plunging prices haven't helped that industry, and its extensive forests are underutilized, making it an insignificant player in the global timber trade. Because of the unfavorable trends in these areas, the Market Vectors Russia ETF (RSX) has lost almost 12% annually over the past three years.

Brazil faces many of the same concerns, as investment vehicles like the iShares MSCI Brazil ETF are dominated by resource giants Vale (VALE 1.82%) and Petroleo Brasileiro (PBR 2.57%), both of which have performed abominably lately. Vale has suffered as a lack of construction demand has sent iron ore prices plunging, and general weakness in commodity metals hasn't given the mining giant much room for growth. Meanwhile, Petrobras keeps struggling with its dual responsibilities as a state-sponsored energy company, with the issue of subsidized fuel for Brazilian residents proving to be politically fraught as the company tries to find ways to boost prices closer to market levels. Brazil's markets are off 15% annually over the past three years in U.S. dollar terms.

Using people power
By contrast, among the BRIC countries, China and India are seen more for their huge populations and business-development prospects than for their natural resources. China has some commodity exposure, but as it expands it will increasingly rely on huge imports of oil, natural gas, and coal to fuel continued economic growth. For the most part, though, China has grown as a result of rising standards of living among the upper echelons of the nation's middle class. India has arguably had a head start over China in that its large population of English speakers gave it more readily available access to the Western world, allowing for trends like outsourcing to take hold and let India take advantage of higher wage levels in developed markets.

Because of their reduced exposure to the natural-resources industry, losses in China and India have been less extreme, ranging in about the 5% range for annualized declines since early 2011 in the iShares China Large Cap ETF (FXI 1.45%), as well as similar India-tracking ETFs. But fears about the sustainability of their respective economic growth rates have impacted India's currency and inflation rates, forcing central bank intervention to try to support the nation's economy. Moreover, concerns have arisen about China's shadow-banking system, creating possible systemic risks that could go beyond the nation's borders.

In short, the these countries might still get labeled as emerging markets, but China is the second-largest economy in the world, and the other members of the BRICs are also seeing their influence in the world grow. If something happens in the BRIC countries to disrupt the way they do business, the impact on the global economy could easily lead to further declines in the Dow.