An escalating European debt crisis may prompt governments to roll out protectionist policies, which would benefit nobody, says global investor Mark Mobius, executive chairman of Templeton Emerging Markets Group.

"With growth in many countries slowing this year (tied in part to the crisis in the eurozone), I’m concerned that protectionism could be on rise. In the end, I believe these policies don’t really protect anyone," Mobius writes in a letter.

Overall, global trade may be slowing but so far, widespread protectionist policies haven't popped up.

Editor's Note: I Wish I Were Wrong — Economist Laments Being Right. See Interview.

But signs they could increase are out there.

"Recently, there has been concern about suspected increases in protectionist policies in Argentina, including import limits, limits on foreign land ownership and nationalization of key resources, particularly in the energy sector," Mobius writes.

"We are closely monitoring this situation, but still see opportunity in a few companies in Argentina that have global operations, and where we see good value potential."

The Argentine government nationalized the YPF oil company earlier this year, seizing a majority stake from Spanish oil giant Repsol.

"Right now we don’t envision Argentina going through a massive nationalization program, but the government is going after some very specific companies, particularly in the oil and gas sector," Mobius writes.

"Natural resources, particularly those that are in high demand and/or are scarce, are often a target of protectionism around the world."

While investors should keep an eye out for protectionist policies, the time to sound the alarm bells isn't now.

"I am watching for harmful protectionist policies closely, but I believe governments engaging in them will recognize these policies are counter-productive, and that they scare investors away," Mobius says.

"I believe policies promoting innovation, efficiency, and fair and free trade are a far better path to growth."

Other noted leaders have expressed concern that protectionism is on the rise, including World Trade Organization Director-General Pascal Lamy, who said recently that protectionist policies across the world's 20 major economies (G-20) now affects 4 percent of the group's trade.

"This time unfortunately the dark spots clearly outnumber the white spots — the overall volume of trade impacted according to our estimation is this time around 3 percent for world trade and 4 percent for G-20 trade," Lamy said recently, according to the AFP newswire.

Editor's Note: I Wish I Were Wrong — Economist Laments Being Right. See Interview.