By Charles Lister, a senior fellow and director of the Syria and Counterterrorism and Extremism programs at the Middle East Institute.
Since Hamas’s brutal attack against Israel on Oct. 7 and the resulting Israeli military campaign in the Gaza Strip, tensions and hostilities across the Middle East have reached fever pitch. And with such a complex regional crisis playing out, it should not come as a surprise that the Biden administration is reconsidering its military priorities in the region.
Since Hamas’s brutal attack against Israel on Oct. 7 and the resulting Israeli military campaign in the Gaza Strip, tensions and hostilities across the Middle East have reached fever pitch. And with such a complex regional crisis playing out, it should not come as a surprise that the Biden administration is reconsidering its military priorities in the region.
It should be cause for significant concern, however, that this could involve a full withdrawal of U.S. troops from Syria. While no definitive decision has been made to leave, four sources within the Defense and State departments said the White House is no longer invested in sustaining a mission that it perceives as unnecessary. Active internal discussions are now underway to determine how and when a withdrawal may take place.
Notwithstanding the catastrophic effect that a withdrawal would have on U.S. and allied influence over the unresolved and acutely volatile crisis in Syria, it would also be a gift to the Islamic State. While significantly weakened, the group is in fact primed for a resurgence in Syria, if given the space to do so.
The unprecedented international intervention launched in 2014 by the United States and more than 80 partner nations to defeat the terror group’s so-called territorial state was remarkably successful, with the final pocket of territory in Syria liberated in early 2019.
In Iraq, too, the Islamic State has almost vanished, degraded to such an extent that in 2023, it averaged just nine attacks a month—down from about 850 per month in 2014.
But the situation in neighboring Syria is more complex. With approximately 900 troops on the ground, the United States is playing an instrumental role in containing and degrading a persistent Islamic State insurgency in northeastern Syria, working alongside its local partners, the Syrian Democratic Forces (SDF).
Yet the threat remains. Early on Jan. 16, an Islamic State rocket attack was launched on an SDF-administered prison holding as many as 5,000 Islamic State prisoners, triggering a mass breakout attempt. While that operation was ultimately foiled, the U.S. deployment also plays a vital role in stabilizing an area in which 10,000 battle-hardened Islamic State militants are detained within at least 20 makeshift prisons and a further 50,000 associated women and children are held in secured camps. As the U.S. Central Command has repeatedly warned, keeping the Islamic State’s “army in waiting” and its “next generation” secured is a vital U.S. national security interest.
While U.S. troops and their SDF partners have managed to contain the Islamic State’s recovery in Syria’s northeast, the situation is far more concerning to the west—on the other side of the Euphrates River, where the Syrian regime is in control, at least on paper.
In this vast expanse of desert, the Islamic State has been engaged in a slow but methodical recovery, exploiting regime indifference and its inability to challenge a fluid desert-based insurgency. In the past few years, the terrorist group has also reestablished an operational presence in regime-held Daraa in southern Syria and markedly expanded the scale, scope, and sophistication of its operations throughout the central desert, temporarily capturing populated territory, seizing and holding gas facilities, and exerting considerable pressure around the strategic town of Palmyra.
In eastern and central Syria, the Islamic State’s shadow influence has returned. The group has reestablished a complex extortion operation, extracting so-called taxes from everyone from doctors and shopkeepers to farmers and truck drivers. With increasing frequency, the Islamic State is issuing them bespoke extortion demands based on acquired knowledge of local business revenue streams. In some cases, Islamic State-branded receipts are issued and when required, and threats are sent to cell phones and relatives.
While much of this activity was initially focused on rural Syria, it is now urban, and in many rural areas, the Islamic State is increasingly recognized as a shadow authority. These far less visible activities may not make media headlines, but they are the core ingredients for a resilient and deeply embedded terrorist insurgency.
For the past several years, the Islamic State has purposely concealed its level of operation in Syria, consistently choosing not to claim responsibility for attacks that it was conducting. Triggered by Israel’s war against Hamas in Gaza, however, the Islamic State has, for the first time, begun to reveal the extent of its Syria recovery for all to see. ISIS thrives on chaos and uncertainty, and there’s no shortage of that in the Middle East these days.
As part of the group’s worldwide campaign to “kill them wherever you find them”, the group conducted and claimed 35 attacks across seven of Syria’s 14 provinces in the first 10 days of 2024—out of 100 attacks worldwide. While the Islamic State remains far from where it was in 2013 and 2014, the group retains concerning capabilities, plenty of confidence, and a newfound sense of momentum. War in Gaza and a spiraling regional crisis are adding fuel to its fire and creating opportunities for the terror group to exploit the situation for its own advantage.
Moreover, the Islamic State’s campaign of intimidation and attacks is beginning to pay dividends in central Syria, where morale within local regime militias is eroding. Throughout the Syrian Badiya, or central desert, the Islamic State has exerted consistent attention on attacking regime security forces along key roadways and outside the region’s extensive network of oil and gas facilities. The scale and sophistication of those attacks increased markedly in 2023, as did their deadliness. According to the Counter Extremism Project, in 2023 alone, the Islamic State conducted at least 212 attacks in Syria’s central desert region, killing at least 502 people. As covert threats and overt attacks increase, reports are emerging with increasing frequency of desertions within regime ranks.
While there is little that U.S. forces can do to alter Islamic State activities within the regime-controlled regions of Syria, U.S. troops are the glue holding together the only meaningful challenge to the Islamic State within a third of Syrian territory. Were that glue to disappear, a significant resurgence in Syria would be all but guaranteed, and a destabilizing spillover into Iraq a certainty.
In many respects, Iraq is key, as the U.S.-led coalition against the Islamic State is effectively headquartered on Iraqi soil. But amid unprecedented hostilities between Iranian proxies and U.S. forces in Iraq, with retaliatory U.S. strikes returning to Baghdad and Iranian-made ballistic missiles targeting U.S. troops on Iraqi soil, pressure is rapidly rising within the Iraqi political system to force a U.S. troop withdrawal from the country.
With Iraqi Prime Minister Mohammed Shia al-Sudani now publicly pushing for a U.S. withdrawal in his own country, some hope remains that the U.S. military’s presence in Iraqi Kurdistan could sustain counter-Islamic State operations, including next door in Syria. This may explain why Iran’s proxies have so frequently targeted U.S. forces stationed at Erbil International Airport in recent weeks.
However, shifting counter-Islamic State coordination from Baghdad to Erbil would present its own complications, sharpening intra-Kurdish tensions between the regional government of Masoud Barzani and the PKK-linked SDF administration in northeast Syria, likely triggering unfavorable Turkish interference. Emboldened by a sense of victory in Iraq-proper, Iran and its proxies in this scenario would then undoubtedly sharpen their attacks on U.S. troops in Syria, seeking their withdrawal too.
Ultimately, events since October have placed the U.S. deployment in northeast Syria on a fraying thread—hence recent internal consideration of a Syria withdrawal. Given the disastrous consequences of the hurried exit from Afghanistan in 2021 and the impending U.S. election later this year, it is hard to grasp why the Biden administration would be considering a withdrawal from Syria. No matter how such a withdrawal was conducted, it would trigger chaos and a swift surge in terror threats. But there can be no denying the clear sense in policy circles that it is being actively considered—and that it has been accepted as an eventual inevitability.
Some within the U.S. government are currently proposing a collaborative arrangement between the SDF and Syria’s regime to counter the Islamic State as an apparent path towards a U.S. withdrawal. That would not only be a phenomenal boon to the Islamic State, but simply impossible on its own terms. Part of the SDF may have periodic contact with Assad’s regime, but they are far from natural allies. The regime would never allow the SDF to sustain itself, and Turkey would do everything possible to kill what remained.
The last time that the Islamic State surged in Syria, in 2014, it transformed international security in profoundly negative ways. Should a U.S. withdrawal precipitate a return to Islamic State chaos, we will be relegated to mere observers, unable to return to a region that we will have placed squarely under the control of a pariah regime and its Russian and Iranian allies.
