Experts have many questions about the ceasefire reached by US Vice President Mike Pence and Turkish President Recep Tayyip Erdogan in Ankara on Thursday.
The 13 points of agreement reached after a four-hour meeting between negotiators fulfil many of the demands by Turkey and the US.
They call for a withdrawal of the People’s Protection Units (YPG) over five days to areas at least 32 kilometres away from the Turkish border in north-east Syria, meeting an important demand for Turkey.
The US government receives Turkish co-operation in the fight against ISIS, and in protecting jails and minorities.
But many questions hang over the agreement, most notably that it does not involve the regime of Syrian President Bashar Al Assad or its strong backer, Russia.
Faysal Itani, a senior fellow at the Atlantic Council, said the document was a strategic win for Mr Erdogan.
"However this plays out, Mr Erdogan can be happy about the US exit and the removal of cover for the YPG, the institutionalisation of his safe zone and the lifting of sanctions," Mr Itani told The National.
He said that as far as implementing the agreement goes, “everything is up in the air.”
“I don't see how we force the YPG to do anything as long as they have the Assad regime as an option," Mr Itani said.
"And I don't see how Turkey takes Qamishli, for example, without conflict with the regime. But overall, these details are not as important as his strategic win."
Nicholas Heras, a senior fellow at the Centre for New American Security, called the deal "a Syrian Democratic Forces surrender document".
Mr Heras said the deal “gives Mr Erdogan just enough time to create enough facts on the ground before his meeting with Russian President Vladimir Putin next week".
“It's a kingly gift from Trump to Erdogan but for this deal to be implementable, it would require Russia to guarantee the security of the local population that has been fighting Turkey's invasion, or alternatively, the complete surrender of the YPG and its agreement to voluntarily be displaced,” he said.
“Neither of those conditions seems to be in the offing.”
It is the Russian role that is crucial for the success or failure of the US-Turkish deal.
Aaron Stein, the Middle East director of the Foreign Policy Research Institute, said he considered the whole document “irrelevant".
“Turkey invaded and the US is leaving,” Mr Stein said. “Turkey sets the tempo and the US reacts.
"Turkey owns the positions of Syria it invaded, and how it chooses to administer the zone is up to Ankara.
“Russia and the regime will have an opinion about this.”
Nicholas Danforth, a fellow at the German Marshall Fund, said: “It is revealing that the two sides still cannot agree on what they agreed on.”
Mr Pence called it a “permanent ceasefire” while the Turkish government says it is a pause in the fighting.
“We get an agreement that the US can say is a ceasefire, Turkey can say isn't a ceasefire, and that doesn't matter anyway because Russia is calling the shots,” Mr Danforth said.
A Russian delegation is already in Turkey for talks on Syria, and the regime in Damascus on Thursday repeated its decision to fight any Turkish presence on its territory.
While the Trump administration said it would lift its sanctions on Turkey, Congressional politicians introducing sanctions bills were committed on Thursday to continue with the process.