Annan travels to Syria on Saturday with the full backing of his successor, UN Secretary General Ban-Ki Moon, who seems to believe that the Nobel Peace Prize laureate is his best and perhaps only chance at the moment to deescalate government violence against the opposition. Annan will also be speaking in the name of the 22-member Arab League, which is growing increasingly critical of the regime of Syrian President Bashar al-Assad.

Experts don't give Annan much chance of achieving a breakthrough in what could be seen as a diplomatic "mission impossible."

"Annan faces very long odds," the president of the International Crisis Group, Louise Arbour, told AFP news agency. "The regime seems determined to crush the protest movement and views any concession as a first step toward its downfall."

With the tacit backing of Russia and China, who have vetoed UN Security Council resolutions condemning the government crackdown on the opposition, Assad's forces bombarded and retook rebel strongholds such as the Homs last week. The United Nations says more than 7,500 civilians have died in Syria's campaigns against anti-Assad protests.

Meanwhile, aid groups are having difficulty even entering the worst-affected areas of Syria to alleviate the considerable human suffering there.

If Annan is to get results, he needs leverage, moral or otherwise, to move the Assad regime. But it is entirely unclear what such a lever could be.

Deaf ears

There has been no shortage of ethical appeals - for instance from the UN General Assembly and the Arab League - to Assad to change course. But thus far, the Syrian President hasn't been listening.

Instead in late February, he presented the Syrian people with constitutional changes that only strengthened his own power. Experts say the changes were intended primarily to send a signal - to the Syrian people and to the West.

"Assad's regime wants to show externally that it is still in control," Middle East expert André Banks from the German Institute of Global and Area Studies in Hamburg told DW.

The government's obstruction of humanitarian missions could prove something of an embarrassment, and China recently signalled it may press Assad to yield somewhat on that score. UN Emergency Relief Coordinator Valerie Amos is scheduled to travel to Damascus on Wednesday, and Annan will surely raise the issue as well.

But on Tuesday, Syrian forces bombed a bridge used by Syrian refugees from Homs to escape to neighboring Lebanon. So moral appeals alone are highly unlikely to put Assad under any real pressure.

Some effect from sanctions

The EU, the US, Turkey and several Arab nations have imposed sanctions on Syria to protest the government crackdown on the opposition. Many are aimed at putting pressure on Syria's oil and banking industries. As a result gas prices and inflation have shot up, and the Syrian national currency has lost value.

But as is often the case with sanctions, ordinary citizens have been the ones to suffer most, as prices for basic necessities like cotton and sugar have risen. And experts doubt that pressure from Syrians unhappy at paying more for basic goods will move Assad.

Moreover, Venezuela is currently increasing its fuel shipments to Syria, and both China and Russia have criticized the idea of sanctions itself. So Assad is unlikely to yield to this sort of pressure.

"That's because the regime still sees that it has external allies," Banks said, adding that he did not believe sanctions could ever force Assad to compromise.

No clear military option

The government's retaking of Homs also raises serious questions as to whether any effective military pressure can be put on Assad.

The so-called Free Syrian Army - largely a collection of deserters from Syria's national armed forces - is regarded as poorly equipped and unable to match Assad's troops. That has led Saudi Arabia and Qatar to moot the idea of foreign military support for the rebels.

"Saudi Arabia has apparently assessed in this situation that a civil war cannot be prevented and is hoping that it can provide resolution," Volker Perthes, Director of the German Institute for International and Security Affairs in Berlin , told DW.

But Perthes added that arming the rebels would increase casualties and that the Syrian government might actually benefit from full-blown civil war since the international community would face pressure not to side directly with either front.

What seems very unlikely is a foreign military intervention along the lines of the one that helped topple Libyan dictator Moammar Gadhafi last year. That's partly down to fear that out-and-out war in Syria could destabilize that country's neighbors.

"There is no pushing through a military intervention," Banks said. "Syria's geo-strategic situation is very different than Libya's."

The United States, which would be crucial to any such intervention, has repeatedly stressed the need for a political solution to the situation in Syria and shown no inclination to get involved militarily.

So it appears that whatever leverage Annan hopes to wield when he visits Syria will probably be of a largely personal nature, making the odds on his achieving a substantial breakthrough there very long indeed.

Author: Diana Hodali/Jefferson Chase
Editor: Rob Mudge