After nearly five years of being written off as a frozen conflict, a new and unprecedented chapter was written over the weekend in Syria’s 13-year civil war. On Wednesday, rebels in the north of the country launched a lightning ground offensive against regime forces and managed, within 72 hours, to take over the major metropolis of Aleppo.
A day later, rebels captured Tal Rifaat, the last major stronghold in northwest Syria that had been held by a third group, the Kurdish-dominated and U.S.-backed Syrian Democratic Forces (SDF).
The significance and speed of the rebel victory in Aleppo cannot be overstated. From 2012 to 2016, thousands of rebel and regime soldiers died in the city—then divided between government and opposition enclaves—in grueling house-to-house battles, with fighters from both sides dying in droves to capture individual streets and move the front line forward meters at a time.
Rebels were expelled from Aleppo in December 2016 following Russia’s intervention on the side of the regime of Bashar al-Assad, in a major blow that preceded a humiliating string of losses for Syria’s opposition over the next eight years. That the entire city would fall so quickly in the past week signals the extent to which the global balance of power has shifted along with the priorities of key regional players—in particular, Russia and Iran.
Unlike in 2016, during last week’s initial rebel advance, Russia’s military assets in Syria—in particular, its powerful air force—did almost nothing to intervene to protect government forces, allowing the rebel ground offensive to advance 20 miles unimpeded toward Aleppo from an opposition stronghold in the province of Idlib.
Russia only began to launch airstrikes in the days after Aleppo was captured in order to halt the rebel advance as it moved farther south and deeper into regime territory, approaching the entrances to Hama in the center of the country.
To many, Moscow’s failure to act quickly in the first three days of the campaign appears inexplicable considering how frequently Russian air power has been deployed over the past year against a low-level Islamic State insurgency in Syria’s central desert area, a far less strategic region and located far from Russia’s large Hmeimim air base along Syria’s coast.
By contrast, Aleppo and Idlib are immediately adjacent to Hmeimim—one of Russia’s largest military bases outside the former Soviet Union—and one that Moscow has relied on since 2018 to transport weapons and thousands of mercenaries and soldiers to war zones across Africa. A symbol of Moscow’s presence in the country, Hmeimim has regularly been targeted by drone strikes carried out by rebels, whose rapid gains over the past week will further threaten the facility along with other key Russian assets in the area.
That Russia did not immediately intervene to arrest the rebel advance has led many to question Moscow’s calculus, including whether the Kremlin intentionally withheld its firepower as a way to pressure Assad to pursue certain political aims—in particular, rapprochement with Turkey, the last patron of Syria’s rebel movement.
Since 2022, Russia has sponsored mediation efforts between Assad and Turkish President Recep Tayyip Erdogan, with the latter hoping to reach a political solution to the conflict that would allow the 4.7 million Syrian refugees living in Turkey to return to their homes, and solicit Assad’s support to counter the U.S.-backed SDF.
For Russia, an internationally recognized political solution would help lift sanctions on Syria and allow for greater investment in the country’s reconstruction—which estimates suggest will cost several hundred billion dollars. Russian companies would be poised to benefit from that effort based on agreements reached with Syria’s government since 2017.
It would also reduce the burden of Russia having to provide for Syria’s defense at a time when Moscow is believed to be suffering some of its heaviest losses yet in Ukraine. However, despite this—and following several failed attempts—Assad and Erdogan still have yet to meet or break ground on negotiations, purportedly due to ongoing disputes over the status of tens of thousands of Turkish troops still in Syria.
Assad’s failure to approach talks in good faith has led many to suspect that Russia and Turkey had prior knowledge of the rebel attack on Aleppo and allowed it to occur in order to bring Assad to the table. According to Reuters (citing opposition sources with ties to Turkish intelligence), before last week’s assault, Turkish authorities reportedly gave rebel forces the green light to attack Aleppo.
The idea that the Russians themselves also would have had advance knowledge of the attack is not implausible. Rebels in Idlib first began to publicly claim in early October 2024 that the movement planned to launch a ground campaign to capture Aleppo, in response to an escalated campaign of suicide drone attacks carried out by Russian and Assad regime forces that began over the summer.
In October, the decision was purportedly vetoed by Turkey, whose military has deployed thousands of troops to rebel-held areas since 2020 to ward off assaults by the Assad regime. This presence has given Turkey significant leverage over rebels, which Ankara has used to enforce agreements reached with Russia in late 2017 that limited the areas that rebels are allowed to deploy to specifically delineated parts of Idlib province.
However, over the past month, Assad’s obstinacy has elicited a series of exasperated statements from Turkish officials, including Hakan Fidan—the foreign minister and former spy chief —who stated in early November that “Assad and his partners do not seem ready to solve certain problems” and adding later in the month—before last week’s assault—that “Bashar al-Assad does not want peace in Syria.”
The recent U.S. election and the beginning of outgoing President Joe Biden’s lame-duck period have also granted Turkey a more permissive window within which Ankara can create facts on the ground that will strengthen its position in any negotiations over the future of Syria. Shortly before last week’s rebel assault, regional media reported that Assad had traveled to Moscow to discuss resuming reconciliation talks with Turkey.
When asked during a press conference on Nov. 29 whether in fact Assad was in Moscow, Kremlin spokesman Dmitry Peskov neither confirmed nor denied the reports, saying, “I have nothing to say on this issue.”
There is more to the story than Russia and Turkey, however. Indeed, the most conspicuous factor contributing to the rebel victory was the vacancy left by some of the regime’s other supporters: Iran and its most powerful proxy force, the Lebanon-based militant group Hezbollah, whose ranks have dwindled over the past two months as a result of Hezbollah’s war against Israel.
Advisors from the Iranian Islamic Revolutionary Guard Corps (IRGC) have led campaigns against Syrian rebels since at least February 2012. Following a string of rebel gains in July 2012, Hezbollah—along with thousands of IRGC-backed Iraqi and Afghan Shiite militias—flooded Syria. For the next 11 years, these forces served as the regime’s shock troops, taking up leading positions along front lines across the country.
More recently, Hezbollah and IRGC forces began to retreat from Syria after Oct. 7, 2023, when Israel stepped up airstrikes against both groups’ leaders concurrent with its war against Hamas in the Gaza Strip. Israel’s killing of several top IRGC commanders in Syria—Razi Mousavi and Mohammad Reza Zahedi on Dec. 25, 2023, and Apr. 1, 2024, respectively, pushed Iran to withdraw hundreds of troops from the country and limit the IRGC and Hezbollah’s front-line presence.
Following the launch of Israel’s offensive in Lebanon in September, thousands of Hezbollah, IRGC, and IRGC-backed Iraqi and Afghan militiamen redeployed again, moving away from major front lines in Syria to instead reinforce weapons-smuggling routes along the Syrian-Lebanese border.
In addition to the loss of Iranian-backed manpower, in May 2024, troops from the Assad regime’s elite 25th Division were also forced to redeploy away from the rebel front line, this time toward Syria’s central desert to put down the growing Islamic State insurgency that has emerged in the area this year.
Without the support of these key forces, Syrian army units still left on the front line found themselves largely defenseless against last week’s rebel advance, led primarily by Hayat Tahrir al-Sham (HTS), a former faction of al Qaeda that controls Idlib province and whose fighters are among the most well-trained and best-equipped in the country.
Even those few IRGC-backed units that remained appeared to offer little resistance. On Nov. 28, after IRGC commander Kiyomars Pourhashemi was killed in clashes with rebels in Aleppo, several hundred Iranian fighters took refuge in the city’s military academy building, where as of this writing they remain, refusing to surrender.
Following the seizure of Aleppo, HTS and its allies continued their push to the south, east, and north, recapturing nearly all territory lost to the Assad regime since 2018 and laying claim to new areas, including the Shiite towns of Nubl and Zahra, which had long served as the staunchest outposts of pro-regime sentiment in the countryside near Aleppo.
On Nov. 30, the Syrian National Army (SNA), another rebel alliance based in the countryside north of Aleppo, launched its own campaign to capture the Kurdish SDF stronghold of Tal Rifaat, linking up with HTS during the fighting to establish a contiguous rebel-held zone covering almost all of Idlib and Aleppo provinces.
As of Dec. 2, rebels have advanced south to reach the entrance of Hama, with clashes ongoing around Zayn al-Abidin Mountain in the city’s northern countryside. Across the country, rebel sympathizers in towns around the large city of Homs and rural parts of southern Syria have also carried out sporadic attacks against regime forces.
Many of these attackers were former rebels who surrendered to Syrian regime forces from 2016 to 2018 in a series of “reconciliation” agreements that allowed the former to keep their weapons in exchange for pledges of loyalty to Assad and his government.
Despite this, many reconciled rebels have continued to take part in a low-level insurgency against Assad’s forces, in particular in the southern province of Daraa, where in March 2020 and July 2021, former rebels fought monthslong battles against regime troops that left dozens of people dead.
In both cases, Daraa’s rebels were only defeated following the intervention of Syrian special forces, which in the latter instance were also backed by Russian airpower. Should HTS-SNA forces continue their march across Syria, reconciled rebels in Daraa and elsewhere could open up a second front, relieving pressure on the former forces and forcing a further collapse along the regime front lines.
The Syrian rebel blitz across Aleppo will create a significant headache for the incoming Trump administration, particularly with regard to U.S. support for the Kurdish SDF, whose forces on Sunday were defeated and expelled from Tal Rifaat after occupying the city and its surrounding towns since 2016.
However the capture of Tal Rifaat represents just the beginning of Turkey’s greater ambitions in Syria, which include dislodging the SDF from all areas that the group controls.
In 2018, during his first term, Trump signaled a desire to withdraw U.S. troops from Syria, doing so later in 2019 following a joint Turkish-SNA assault on the SDF that forced the latter to relinquish control of key towns along the Syrian-Turkish border. Now, following the recent gains by the HTS and the SNA rebel militias, the SDF and the United States will be under even more pressure from Ankara to withdraw from Syria.
Such a withdrawal would likely trigger another resurgence of Islamic State, which Syria expert Charles Lister reports has tripled its rate of attacks across the country since 2023. The group’s resurgence was largely made possible due to the vacuum created both by the retreat of IRGC-backed forces and the withdrawal of several thousand Russian mercenaries and troops following Moscow’s invasion of Ukraine and the attempted Wagner Group mutiny in Rostov-on-Don in June 2023.
The U.S.-backed SDF has been critical to stemming the flow of Islamic State attacks. Should the group be forced to confront a resurgent rebel force backed by Turkish airpower, such trends may only get worse.
That said, if Turkey, HTS, or the SNA launch renewed attacks against other SDF-held areas—particularly around the city of Manbij—then U.S. troops will either be forced to confront a far stronger and more empowered rebel force backed by Turkish air power or withdraw.
Trump will be under significant pressure in Washington to avoid the latter option, which would invite all three actors to launch new assaults into SDF territory, similar to the Turkish-SNA campaign in 2019 and HTS’s capture of Aleppo over the weekend. SDF territory—which extends deep into the desert of eastern Syria—is also adjacent to areas with a significant buildup of Iranian troops, who could also exploit a U.S. withdrawal to seize new territory for themselves.
This dilemma could very well serve as the first foreign-policy challenge of Trump’s second term, with the president caught between the isolationist wing of his party and more hawkish voices that have made opposition to Iran and terrorist groups—including the Islamic State—a core plank of White House foreign policy.
