Embedded in the euro and thus no longer in control of its own currency, Greece cannot take the easy way out of its debt by devaluing. So Greece must either cut its spending sharply or default on its loans — which would badly damage German and French banks carrying a lot of Greek debt.

That is considered one reason President Nicolas Sarkozy of France has been so quiet on the Greek crisis, Mr. Fitoussi said. The Greek deal “is an indirect way of bailing out French and German banks,” he said. “The French understood this from the start, but Germany didn’t seem to.”

Katinka Barysch, an economist and deputy director of the Center for European Reform in London, said that that realization had hit home in Germany. “It might be unpopular for the Germans and Europeans to bail out Greece, but it will be even more unpopular for them to bail out the banks that owned Greek bonds,” she said.

Thomas Piketty, the founder of the Paris School of Economics and a professor there, thinks that the demands on Greece, driven by a market frenzy, are simply too high.

“Austerity can be justified, but 8 percent interest rates on a debt that amounts to more than 100 percent of gross domestic product is just crazy,” he said. “They will have to restore their public finances and then pay back this huge debt at the same time — and Greek debt amounts to so little when you compare it to what was needed to bail out the banks” last year.

“Not only is this not going to help growth, it’s going to end very badly, politically speaking,” Mr. Piketty said, referring to Greece. “Taxpayers cannot accept this in the long run.”

On Sunday, the Greek finance minister, George Papaconstantinou, forecast a deeper than expected recession of 4 percent for 2010 and 2.6 percent in 2011, before the economy supposedly returns to growth of 1.1 percent in 2012. “We will be in recession for the next few years, which means that we have to run faster to reduce the deficit,” he said.