The Syrian government's biggest international backers and opponents plunged into negotiations today over a long-sought compromise to help end a 4 and-a-half year civil war and potentially ease President Bashar Assad out of power.
US Secretary of State John Kerry said he was hopeful of finding a path forward.
In Austria's capital, Kerry was negotiating with foreign ministers and senior representatives of 18 other countries. They included Iran for the first time, making it the broadest gathering of nations yet to discuss Syria's future.
Another key supporter of Assad, Russia, was present, along with many of the most influential Arab and European allies of the United States.
Several participants argued that the talks themselves were a sign of progress.
But with no end to the war in sight, there was pressure on all sides to begin chipping away at a "political transition" plan that might convince Assad's government and the vast array of armed rebel groups to stop fighting and allow world powers to focus on their shared commitment to defeat the Islamic State. A breakthrough wasn't immediately apparent.
As the Vienna talks were happening, Syrian opposition reported that a government missile barrage killed more than 40 in a Damascus suburb. The conflict has claimed more than 250,000 lives and uprooted more than 11 million people since 2001, leading to the growing terrorist threat of the Islamic State and sparking a refugee crisis throughout Europe.
"I am hopeful that we can find a way forward," Kerry told reporters, before adding: "It is very difficult."
Assad's fate was at the centre of discussions. The US, Saudi Arabia and others have tempered their earlier calls for Assad's immediate ouster and now say he can remain in office for months as part of a transition if he agrees to resign at the end of the process.
Russia and Iran are both providing Assad military assistance and say Syria's leadership shouldn't be dictated by outside forces.
Offering some hope, however, both countries have suggested greater flexibility in recent weeks.
Western diplomats have spoken of various conversations with their Russian counterparts indicating that the Kremlin is not "wedded" to Assad maintaining control of the country. And senior Iranian diplomat Hossein Amir Abdollahain told The Guardian last week, "We are not working for Assad to stay in power forever as president."
But no one has provided any clear indication of what the transition process might look like and how long it would take or if either of the Syrian sides would be ready to support such a plan.
Assad, a member of Syria's Alawite minority, won re-election last year in a vote that Western countries called a sham and his term ends in 2021. The Sunni-led opposition wants him out immediately.
