When Staffan de Mistura took over as special United Nations representative on the Syria crisis - with the task of ending the violence - he faced a mission impossible.
Three years of brutal civil war have smashed the country to bits, with major cities reduced to rubble. About 200,000 Syrians have died, eight million (out of a population of 22 million) are internally displaced, and three million are refugees in neighboring countries. The chaos has spawned ISIS.
De Mistura's two predecessors, both distinguished diplomats, gave up after failing to jump-start a broad peace process in Geneva. The Assad regime, backed by Russia and Iran, wouldn't budge. Sunni rebels, backed by the Gulf states and (halfheartedly) by Washington, were fragmented.
So this urbane Italian-Swedish diplomat knew he had to address the problem from a different angle. Decades of experience in conflict zones from Kosovo to Iraq to Afghanistan haven't dimmed his positive outlook, but have destroyed any illusions.
"I came to the conclusion at this stage that we needed to try a different way," he told me from Rome in a phone interview. Instead of going big - and promoting another top-down Geneva peace plan - de Mistura decided to start small.
His plan - he stresses that it is an "action plan," not a "peace plan" - is to work bottom-up and try to "freeze" the violence in certain locations. The aim is to persuade the regime and rebel groups to stop the violence, permit humanitarian aid, and try to begin a local dialogue among factions. If a "freeze" worked in one city, it might provide the impetus for another, ultimately leading to a broader political dialogue.
Skeptics deride the idea, but I think it's worth a closer look.
The first place de Mistura wants to test his idea is historic Aleppo. Once Syria's largest and richest city, it is now caught in a brutal three-way battle by regime forces, rebel groups, and ISIS. Regime barrel bombs have slaughtered civilians, and the ancient town center has been devastated by shelling.
Why start there? "Because it is symbolic," de Mistura replied, "a city that is home to all religious groups and the last major city that is contested. ISIS is waiting to take advantage . If we can succeed there, we can use it as a sign of hope."
By a "freeze," de Mistura doesn't mean the kind of local cease-fire accepted by desperate rebels in other cities, such as Homs, where they gave up all but their light arms and essentially accepted defeat. His idea is that all sides would stop in place, with rebels keeping their weapons.
What if ISIS refused a freeze after the other two sides accepted? "It would be up to the American-led coalition to address the threat of ISIS, if ISIS threatens a city where the conflict had been frozen," he said. "I hope the American-led coalition would signal that this would be a bad idea."
Skeptics will note that Bashar al-Assad is on the verge of defeating the dozen or so non-jihadi rebel groups in Aleppo, who are caught between the regime and ISIS. So why would he stop now? De Mistura, who had an "intense" meeting with Assad, answers carefully when I ask if the Syrian president would agree to a freeze: "He has indicated publicly that he would consider this, but the devil is in the details." He added that Russian Foreign Minister Sergey Lavrov has "indicated that [Assad] would give this a chance."
Other Syria experts are more dubious. "De Mistura is scrambling to find the key to a political-diplomatic process, one in which Assad is profoundly uninterested [because he] believes Iran and Russia will keep the regime in its seat," says Fred Hof, a former senior State Department official now at the Atlantic Council.
However, there are reasons why Assad might consider a freeze.
"The regime doesn't want to go in and take Aleppo," says Joshua Landis of the University of Oklahoma. "It just doesn't want the rebels to have it." A freeze in Aleppo would enable Assad to focus on attacking rebels elsewhere.
Not surprisingly, while some rebels in Aleppo are interested in the freeze because it would save them and many civilians, rebel groups outside are wary. De Mistura is trying to convince them that "what is at stake is the survival of their own people and saving Aleppo."
In the end, the rebels might accept a freeze to prevent the fall of Aleppo, the last major city in which they have a foothold. This would give them a breather as they wait for Washington to decide whether to endorse a buffer zone along the Syrian-Turkish border, where refugees could find safety and moderate rebels could train.
The real question is whether a freeze in Aleppo could lead to incremental freezes elsewhere, which could ultimately foster a larger peace process. That is harder to imagine.
Still, de Mistura, who could be relaxing on the Isle of Capri, where he is honorary Swedish consul, is instead plowing ahead, propelled by his belief that "everybody in Syria has become tired, everyone agrees there is no military solution, everyone is a loser."
"He's doing the best he can in a limited situation," says Landis. "You have to go small with a prayer, to be there on the ground if an opening occurs in the future."
Hats off to de Mistura. Sisyphus had an easier task.