The US has stepped closer towards an alliance that could change the Middle East by no longer regarding Hayat Tahrir Al Sham, Syria's post-Assad rulers, as terrorists.
The administration of President Donald Trump made public an official revocation of the US's foreign terrorist organisation designation for HTS. The group has been in control of most of Syria since the downfall of the Assad regime in December. Current Syrian President Ahmad Al Shara founded HTS a decade ago after breaking away from Al Qaeda.
A senior European source said that by removing the terrorism designation, Washington is telling Mr Al Shara “and his men that you are under American protection". The two sides "have become allies”, the source added.
The decision was in part technical because, without it, Mr Trump would not be able to proceed with his decision to lift US sanctions on Syria, observers said.
However, it was also necessary to enable international business in Syria, the European source said. “If you want a commercial agency in Syria, or to sign an infrastructure or any major contract, ultimately you need to have contact with HTS,” the source said. “They control everything."
A Syrian source who has been in contact with American officials about the sanctions said both Washington and Damascus "are taking a baazari approach", consisting of "if you do this, we do that".

The source pointed out that Syria remains listed as a state sponsor of terrorism and that senior figures of HTS remain designated terrorists. The US imposed the state-sponsorship of terrorism designation on Syria in the late 1970s, over Hafez’s Al Assad's support for radical groups in the region.
Mr Al Shara, the militant-turned-politician has made establishing ties with Washington a central pillar of Syria’s foreign policy, accommodating demands by Washington to curb extremists and talk to Israel, although both Syrian and Israeli officials have described such talks as indirect.
Reassuring responses
Urged by Turkey and Saudi Arabia, Mr Al Shara’s main international supporters, Mr Trump announced a decision to lift US sanctions on Syria on May 13. He met Mr Al Shara in Riyadh shortly afterwards but the sanctions removal did not become formal until the end of last month.
The US measures were toughened considerably after Syrian security forces killed thousands of civilians in a crackdown on a peaceful protest movement that demanded the removal of Bashar Al Assad, which broke out in March 2011.
The crushing of the protests by the Alawite regime led to a violent Sunni backlash and the creation of rebel groups that HTS eventually overtook.
US officials have said supporting the new government in Damascus was important to stop a meltdown of Syria's economy, a main factor behind the downfall of the former regime, and potentially reigniting the chaos that blighted the country throughout its civil war.
Consolidating the new order was also necessary to prevent Iran from establishing itself and its militia allies in Syria, the officials added.

A Sunni ascendancy that replaced the Russian and Iranian-sponsored order in Syria has undermined a so-called Shiite crescent, underpinned by sectarian identity and anti-Israeli ideology.
The term, describing the Iranian takeover of decision-making in Baghdad, Damascus and Beirut, was coined by Jordan's King Abdullah II after Iraq started falling under Iran's orbit in the 2000s.
On Monday, Israeli Prime Minister Benjamin Netanyahu met Mr Trump in Washington and said the post-Al Assad order "presents opportunities" for eventual peace.
Syrian political researcher Waiel Olwan said the Syrian government has signalled to Washington that "it is willing to sit at the table and reach a regional arrangement".
However, reaching a deal has been complicated by Israeli incursions into Syria in recent months – beyond the already occupied Golan Heights – and Israel's apparent refusal to meet Syrian demands to return to a 1974 armistice line.
Possible Israeli-Syrian ties require solving "a lot of details", said Mr Olwan, senior researcher at the Jusoor Centre for Studies.
"The Americans are receiving positive and reassuring responses from the Syrian government," he said from Damascus. However, he expected Washington to "wait before removing all the pressure cards on Syria”.