The announcement of a nationwide ceasefire in Syria brokered by Russia and Turkey was met with a strong dose of skepticism Thursday, particularly because two previous brokered deals this year collapsed within weeks.
In fact, clashes broke out early Friday between rebels and Syrian government forces just hours after Russian President Vladimir Putin announced the agreement between government and opposition groups who have waged battle for nearly six years.
The deal, according to Putin, will be guaranteed by Moscow — which backs Syrian President Bashar al-Assad — and Turkey, which supports the opposition forces. Iran, a key ally of Assad, also supports the deal.
Putin has said the ceasefire will be followed by peace talks next month in Kazakhstan.
Here's what else we know about the deal.
Who is included in this ceasefire?
The truce is said to include Syrian government forces and 62,000 opposition fighters across the country. At least 13 armed opposition factions have signed the five-point agreement and have said they will abide by the ceasefire, according to Osama Abo Zayd, a spokesman for moderate Syrian opposition groups.
Who isn't included?
Many rebel groups have yet to sign on and several extremist groups, including Islamic State in Iraq and Syria (ISIS), the al-Qaeda-linked Fatah al-Sham Front and Jabhat Fateh al-Sham (formerly known as al-Nusra), were reportedly excluded from the deal.
How is this ceasefire different from the others?
Two previous agreements this year, brokered by the U.S. and Russia, quickly collapsed. But this is the first attempt by Russia and Turkey to broker a comprehensive ceasefire.
Why it might falter
There are hundreds of rebel groups in the Syrian rebel landscape, and many have yet to indicate they will abide by the ceasefire.
"That's one of the main reasons they tend to fall apart," said Emily Hawthorne, a Middle East and North Africa analyst for the U.S.-based intelligence firm Stratfor. "We have no reason to think that this time will be any different."
Why it might hold
Though not optimistic, Hawthorne acknowledged there are a couple potentially important differences with this deal, including the fact it comes after the rebels lost Aleppo, following their massive four-year offensive against the government in the city.
"There is a certain desire on the rebel side to coalesce, to regroup, to rest. So there is hope in that sense that the rebels might want to take this opportunity to focus on regrouping," she said.
As for the government forces, they are eager to focus their resources on ISIS, she said.
"There are reasons on the battleground that make it such that some of these actors are willing to abide by a ceasefire on the rebel side and on the loyalist side," she said. "Doesn't mean we should embrace this with a whole lot of hope."
While clashes have already been reported, Hawthorne said there needs to be some major infractions to scuttle the ceasefire, like a an airstrike or repeated airstrikes.
"Still going to have fire on some of these fronts. We still expect to see some shelling, some violent activity. Still wouldn't mean the ceasefire is called off."
What's in it for Russia and Turkey?
Professor David Lesch of Trinity University says Moscow is motivated, in part, to gain more geopolitical prominence and be seen as the arbiter of the Syrian conflict.
"This will be a tremendous propaganda victory if they can at least be perceived to be doing this without the United States," said the Texas-based history professor who specializes in Syria.
But Russia is also looking to draw down its forces in Syria while maintaining a presence.
"They can't do that without helping to bring about a political negotiation and the first step to that is absolutely a ceasefire," Hawthorne said.
Meanwhile, Turkey's main goal is preventing any establishment of a Kurdish corridor adjacent to its border with Syria.
"For Turkey, it's all about the Kurds," Lesch said. "This is why they've improved relations with Russia and why they're included in this deal for the ceasefire. Right now, they think that co-operation with Russia will get them closer with what they want strategically with the Kurds."
What does this mean for Assad?
Assad's term officially expires in 2021, and it's possible he could hang on to power until then.
Lesch says the Russians seem to want Assad to step down in 2021 in a "face-saving way" and as part of a transitional move that would still protect Russian interests.
Turkish President Recep Tayyip Erdogan has a strong disdain for Assad but might take a pragmatic approach in political negotiations, Hawthorne said.
"They will have to prioritize. Do they care more about the Kurds? Do they care more about who is ruling in Damascus? They're going to pick a political resolution that helps them keep that northern [Syrian] territory under their firm watch and influence so they don't see a federal Kurdish state popping up over the border."
She says Iran could spoil Erdogan's hopes of ousting Assad because it wants to ensure Assad and his core group of elites remain in order to channel Iranian power in the region.
But Iran might agree to Assad stepping down, as long as he's succeeded by another powerful Alawite who will protect Iranian interests, Lesch said.
"If Russia and Iran can be convinced that their strategic interests will be protected with Assad stepping down, they will be for that.
"But that doesn't mean Assad would be in agreement with this and ultimately he has the last say."