The big winners this time, according to bankers and investors, were American and European hedge funds like Greylock Capital, Fir Tree, Brevan Howard and Third Point, all of which snapped up Greek debt last summer as warnings grew that Greece might leave the euro and default on its debt. Many have booked gains of 100 percent or higher.

They largely have the financial lobby to thank — in particular the Institute of International Finance, which is based in Washington and represents the interests of more than 450 banks, hedge funds and other financial institutions around the world. The institute played on fears in Brussels, Rome and Madrid that a hard-line approach to the hedge funds would create another round of market chaos.

The warning was blunt: If Athens set off legal mechanisms in the bond contracts known as collective action clauses, forcing bondholders to accept lower prices, investors would stop buying the bonds of struggling European countries. That would be bad news for Spain and Italy — to say nothing of Portugal and Ireland when they return to global bond markets in 2013.

Countering this pro-hedge-fund argument was a small circle of bankers, lawyers and policy advocates, the most prominent of whom was Mr. Wohlin, the Deutsche Bank executive who sent the e-mail. Another was Adam Lerrick, a former investment banker now affiliated with the American Enterprise Institute.

They argued that collective action clauses have a legitimate function: to help near-bankrupt countries reach debt restructuring agreements with a majority of their bondholders, with a minimum of legal fuss from investors holding out for a better deal. All euro zone countries that issue debt next year will have such clauses in their bond contracts, and proponents say there is scant evidence that they cause market turmoil.

“If you use these features within the rules, they should not cause any disruption,” said Jeromin Zettelmeyer, a sovereign debt specialist at the European Bank for Reconstruction and Development.