Castaldi, in a paper published shortly after Greece received a $150 billion bailout in May 2010, argued the response showed a “complete lack of European leadership.” He wrote there is “glory waiting around the corner” for European leaders who create a true fiscal union and European treasury.

The current Merkel-Sarkozy proposal doesn’t strive for such financial unity. After meeting Monday in Paris, the two leaders said that they’ll push for a new or revised EU treaty that imposes penalties on governments that violate debt and budget limits. They also want the changes written into state constitutions.

Sarkozy, who faces a reelection fight next year, is reluctant to relinquish sovereignty to a fiscal union favored by Merkel. The German leader, meanwhile, opposes Sarkozy’s desire to unleash the European Central Bank as a lender of last resort.

“Merkel is on the right path but doesn’t see the urgency,” Castaldi said. “Sarkozy sees the urgency but he’s on the wrong path.”

As if they needed more pressure, Standard & Poor’s credit ratings agency warned late Monday that it may downgrade euro zone countries, including Germany and France, if there’s no progress. It later said it may also downgrade the EU’s top rating.

World leaders have exerted extreme pressure on Merkel, in particular, for a solution. She’s the head of Europe’s largest and strongest economy. Any fix needs the support of Germany. But her failure to act has made things much worse.

What began as a comparatively small debt problem in Greece — which accounts for just 3 percent of all euro zone public debt — has become a crisis threatening to decimate the global economy.

Most economists agree that the ECB could save the euro by acting as a lender of last resort to indebted governments shunned by the bond market. Mario Draghi, the ECB president, hinted last week — in central banker-speak — that if there’s a “fiscal compact” that “other elements might follow.” The bank’s governing council meets Thursday in Frankfurt.

But Merkel, who warns that an ECB buying spree would spark inflation, said last Friday that the solution is more akin to a marathon than a sprint. A quick fix wouldn’t address “fundamental flaws in the construction of the euro,” she said, alluding to a monetary union that lacks a treasury.

Of course, things didn’t end well for the original marathoner. The Greek messenger who ran to Athens to deliver news of the Athenian victory over Persians at the Battle of Marathon dropped dead after completing his task, legend has it.

The euro may await a similar fate unless leaders quickly agree on a blueprint for a fiscal union and treasury, argues Castaldi. Broad support now for this long-term goal would be enough to calm market fears, he said, adding he agrees with German reluctance about inflation because it’s “the worst of the taxes. It punishes the poor.”

Still, the “Merkozy” plan for constitutional changes and tougher budget oversight is “better than the current situation,” he said, and it’s “promising” that they set a March deadline for treaty changes.

And Larres is confident that “a solution will be found. One wonders if it could have been found earlier in the crisis.”

Despite the criticism, Merkel and Sarkozy are seeing better poll numbers at home. Sarkozy’s numbers are up several points to 37 percent, according to French media reports. That still leaves him far behind Socialist challenger Francois Hollande in May’s election, however.

In Germany, a recent poll for ZDF Television showed 56 percent of respondents said Merkel is handling the crisis well, and 78 percent believe the euro will survive.

But do Merkel and Sarkozy possess the charm and persuasiveness needed to sell a plan to potentially skeptical peers?

“An aura of personal gravitas always helps,” said Larres, author of a book about Winston Churchill’s leadership skills. “That is lacking in Merkel and Sarkozy.”

Great leaders guide public opinion rather than follow it, Larres said, noting that Merkel has been criticized “for looking too much at the opinion polls.”

“To be fair, she doesn’t incorporate that strong pro-European outlook that Helmut Kohl and other leaders have had,” Larres said. “It’s not in Angela Merkel’s blood.” Merkel, the daughter of a Protestant pastor, grew up behind the Iron Curtain in east Germany. She speaks Russian.

Castaldi adds that Sarkozy and Merkel “are from a younger generation.”

“They are not those who have seen the war, which has always been the basic inspiration and reason for European integration,” he said.

The euro, he said, “is not their history and this was not their battle. They are there, though and they cannot choose. They have the crisis and the only positive answer is to go for more Europe, to go for a political union.”

Earlier this year, Kohl criticized Merkel in the German media, saying there can be “no excuse for having no view or idea where you belong and where you are going.”

The revered former chancellor who led Germany through reunification and later into the euro used his aura of gravitas to successfully advocate for his ideas despite public resistance.

“It was very difficult to convince the Germans that they had to give up the Deutsche mark, but he did it, with good reasons and good arguments,” Castaldi said.

“It would have been much better,” he continued, “if Ms. Merkel had taken the lead at the beginning. We would not be here in the first place.”

Specifically, when Greece sought aid to avert bankruptcy in early 2010, the greatest fear was that debt concerns would spread to other weak euro nations. Europe’s plan was simple: Fix Greece and the crisis is contained.

But Merkel’s government held out until the last minute before approving its share of a $150 billion bailout. Paying Greece’s generous pensions was deeply unpopular among Germans. Merkel was accused of stalling to avoid a backlash in a regional election, which her party lost anyway.

In a dramatic speech in Berlin last week, Polish Foreign Affairs Minister Radek Sikorski told German leaders that it is up to them to fix the problem.

“Because of your size and your history you have a special responsibility to preserve peace and democracy on the continent,” he said. “I fear German power less than I am beginning to fear German inactivity. You have become Europe’s indispensable nation. You may not fail to lead.”

Future generations “will judge us by what we do, or fail to do,” he said.

“As a Pole and a European, here in Berlin, I say: The time to act is now.”