But even as its proto-state crumbles in the face of multiple assaults, experts warn Daesh remains a potent threat whose ideology is likely to endure long after its “caliphate” is gone.
After more than four months of fighting to retake Raqqa, the US-backed Syrian Democratic Forces (SDF) declared the city liberated on Tuesday, seizing what was once the terrorists’ de facto Syrian capital.
The loss is only the latest in a string of blows against Daesh, which has lost swathes of territory to the SDF, the Syrian regime and to Iraqi forces the other side of the border.
With the loss of Raqqa, the “would-be caliphate of IS (Daesh) that at its height in 2014 threatened to rule all of Syria from Aleppo to the Iraqi border will be cut down to a dwarf territory in Deir Ezzor,” said Nicholas Heras, a fellow at the Center for a New American Security.
The eastern Syrian province, which borders Iraq, “will be the center of gravity for IS (Daesh) in Syria,” he said.
“IS (Daesh) always intended for Deir Ezzor and its neighboring area... to be the last stronghold of the caliphate.”
The province’s remote location in “harsh desert” far from both Damascus and Baghdad makes it the perfect place for a last stand, he added.
But the jihadists are already under attack across the province, and losing territory to two separate campaigns.
The first, on the eastern bank of the Euphrates river that slices diagonally across the province, is being waged by the SDF with US-led coalition support.
The second is a Russian-backed Syrian regime operation, which has already broken a nearly three-year siege of government-held parts of provincial capital Deir Ezzor city and seized the strategic town of Mayadeen.
“I think the Iraqi and Syrian governments will work to secure the whole border, knowing that neglect of the porous border area will only abet IS in the future,” said Aymenn Jawad Al-Tamimi, an expert on counter-terrorism.
For Syria’s regime and its ally Iran, a victory in the area would be doubly valuable, cutting off further advances by the US-backed SDF and ensuring Washington cannot block Iran’s land route through Iran into Syria and Lebanon.
Despite suffering major losses of territory, Daesh will remain a dangerous threat for the foreseeable future, experts say.
“The awful truth is that IS will be just as deadly as an insurgency and a terrorist network as it was as a state-like actor,” Heras said.
Al-Tamimi said the group would likely use raids, sleeper cells, improvised explosive devices and suicide bombings even after its core territory has disappeared.
“Attacks in Europe will continue for some time. I think the defeat of IS (Daesh) as a state project does diminish its appeal, but there will be supporters for a long time to come,” he said.
Charlie Winter, a senior research fellow at the International Center for the Study of Radicalization and Political Violence, warned that the ideology of Daesh would linger long after its “caliphate” was gone.
He said the group saw itself as successful, having “managed to declare a caliphate and keep it going” — something unprecedented in modern terrorism.
That, he added, “will have an impact on the global jihadist spectrum for years and years to come.”