Remnants of the Islamic State are engaged in a campaign of violence, extortion, and terrorism in Syria and Iraq in an apparent effort to regroup after the disintegration of the jihadist group's land caliphate earlier this year.
These ISIS fighters have reverted to insurgent tactics, forcing U.S.-backed Syrian Democratic Forces and Iraqi security forces to adjust their strategy from the focus on countering a conventional threat. Some experts are concerned this could be a sign the group is preparing to make a push to retake lost territory.
The SDF, supported by U.S.-led Operation Inherent Resolve forces, has conducted more than 50 operations targeting ISIS "sleeper cells" in northeast Syria since the defeat of the land caliphate on March 23, according to U.S. Central Command. They have reportedly led to the capture of more than 140 ISIS fighters and the removal of more than 3,000 improvised explosive devices and unexploded ordnance.
One of the most recent operations took out a cell in Abu Naytl on June 18. ISIS members were trying to incite violence and threaten tribal leaders before a contingent of 1,000 SDF soldiers cleared them from the Syrian town.
"Operations like this show just how much progress has been made in destroying Daesh," Maj. Gen. Christopher Ghika, deputy commander for stability for Operation Inherent Resolve, the mission to defeat ISIS, said in a statement Friday, using another term for the terrorist group.
"But that doesn't mean the fight is won," Ghika said. "Daesh doesn't need territory to remain a global and regional threat as it attempts to resurge. Our resolve remains firm, and we will continue to assist our partners in consolidating their gains and pursuing the remnants of Daesh."
SDF counterterrorism units reportedly arrested five ISIS sleeper cell members Wednesday in Raqqa and Manbij. Both cities were caliphate strongholds. Members of the Raqqa Internal Security Forces, a police unit formed in 2017 after the fall of ISIS in the city, arrested six ISIS members in April who were allegedly responsible for explosive attacks against civilians in the area. Another 63 were captured in Raqqa in February.
Neighboring Iraq has fallen victim to similar attacks. The Iraqi Civil Defense Directorate said that more than 6,100 acres of agricultural crops were incinerated by ISIS agents over the course of two weeks in May. ISIS said these attacks were retaliation against farmers who refused to pay them protection money. Other ISIS members have reportedly engaged in sniper attacks and suicide bombings.
Jennifer Cafarella, research director for the Institute for the Study of War, told the Washington Examiner that referring to the cells as sleepers takes away from the fact they are organized units focused on degrading and delegitimizing local governments.
"To me, they're not isolated pockets of surviving ISIS remnants but rather a reconstituting insurgent force akin to the force, for instance, that the U.S. faced in Iraq during the surge," Cafarella said, referring to the additional U.S. troops sent to Iraq in 2007.
Some experts and national security officials expected ISIS to revert to its insurgent origins after the defeat of its land caliphate. The group has also made significant advances in other parts of the globe. In April, terrorists believed to have had ties to ISIS killed 258 people and injured at least 500 in a series of Easter Sunday bombings in Sri Lanka. An ISIS affiliate in the Philippines killed 20 people and injured more than 100 in the January suicide bombing of Jolo Cathedral.
ISIS presence in Africa has grown significantly since the fall of the caliphate. In a video message released in April, ISIS leader Abu Bakr al-Baghdadi praised adherents in Libya for a successful attack in the desert town of Fuqaha and noted forces in Burkina Faso and Mali have pledged allegiance to him.
Cafarella believes ISIS, despite major losses, wants to reestablish its land caliphate in Iraq and Syria and expand its presence across the globe. She pointed to the group declaring itself to be in a "battle of attrition" on May 29 as evidence of its intentions. ISIS engages in these phases on a yearly basis, so Cafarella expects the group to make a move next summer.
"I think the open question is whether ISIS will set enough conditions in its favor by that time to attempt a new land grab or whether it will determine that it needs to conduct another phase of operations to degrade its enemies in advance of the land grab," Cafarella said.
U.S. Central Command continues to work with local partners in its fight against ISIS, but as defense officials continue to reorient the military to take on competitors like China, there are concerns among some experts that the ISIS fight will be overlooked.
