The rescue package devised by the euro zone and International Monetary Fund (IMF) for Greece has proven ineffective, says Mohamed El-Erian, CEO of money management titan Pimco.

And that ineffectiveness has ominous implications for the global financial system, because Greece is just one of many industrialized nations with huge financial problems.

“The triumphant Greece/European Union/IMF announcement of a couple of weeks ago has not calmed markets, nor has it lowered Greek borrowing costs,” El-Erian recently wrote in the Financial Times.

“In fact, market measures of risk signal more concern today than before the announcement.”

Greek stocks and bonds are plunging, and the euro has dropped to a 10-month low against the dollar.

The Greek aid package suffers from a lack of trust among participating countries, El-Erian says.

Meanwhile, financial markets elsewhere have been rolling merrily along.

“Buoyed by a cyclical recovery, markets around the world have yet to recognize the complexity of this situation,” he wrote.

“When they do, it will also become apparent that Greece is part of a wider and historically unfamiliar phenomenon – that of a simultaneous and large disruption to the balance sheet of many industrial countries.”

El-Erian’s advice: “Tighten your seat belts.”

Greece’s woes already threaten Europe’s economic recovery.

“The indirect impact from the Greek case is that we will see more fiscal tightening from several euro zone members earlier than the ECB thought, which is slowing down the recovery,” Carsten Brzeski, an economist at ING, told Bloomberg.