Attachments
Rebels have captured Aleppo, the country’s second most significant city, abruptly throwing the Syrian government on the back foot. In this Q&A, Crisis Group experts explain what has happened and how the various parties to Syria’s conflict may react.
What is happening?
Syria’s civil war, which has been largely frozen for over four years, has erupted again in startling fashion. Rebels who control Idlib province and adjacent parts of north-western Syria broke through the Syrian army’s lines, driving east, capturing Aleppo, the country’s second city, and cutting the crucial M5 highway connecting it to the capital Damascus in a matter of days.
The offensive has overturned a delicate set of arrangements that had kept fighting in the north west fairly quiet since 2020, when Russia and Türkiye struck a ceasefire deal that froze the front lines. That ceasefire, which covered actions by Syrian government forces and its allied militias, on one side, and rebels, on the other, had largely held despite frequent shelling across the front. The relative calm allowed Hei’at Tahrir al-Sham (HTS), the main rebel group, to assert dominance in Idlib, ensconce itself as a military force and establish a civilian government it backed, the Syrian Salvation Government. HTS has also indirectly benefited from the support Türkiye has extended to the Syrian National Army (SNA), an umbrella group comprising several other rebel factions.
The speed of the rebels’ advance is surprising, but the fact that they attacked is not. HTS – a former al-Qaeda affiliate that broke with the global movement in 2016 and swore off transnational jihadism – has never wavered from its goal, which it shares with other rebels, of ending President Bashar al-Assad’s rule. Even as it focused on governing territory under its control, it was waiting for the right opportunity to gain ground. Since 2020, when major combat on the north-western front paused, it has been building up its forces with the help of defected Syrian military officers who have improved its fighters’ skills, its units’ command-and-control and its general coordination. HTS and associated groups are more organised, more disciplined and better equipped than before. They have also been using new weaponry, particularly drones, as a force multiplier.
The rebels’ opportunity arrived due to a chain of events that have chipped away at the Syrian government’s strength on the ground.
The rebels’ opportunity arrived due to a chain of events that have chipped away at the Syrian government’s strength on the ground. Since 2022, when it launched its all-out invasion of Ukraine, Russia has diverted its attention from Syria to concentrate its forces in the battle with Kyiv. The next links were Hamas’ attack on Israel on 7 October 2023, the subsequent war between Israel and members of the Iran-led “axis of resistance”, and the heavy blows that Iran and Hizbollah in Lebanon, in particular, have suffered in the past few months. Hizbollah, whose fighters are known for their professionalism and ability to hold lines, and other Iran-backed militants have long deployed troops in the north west and elsewhere to aid the Syrian government. Since 7 October 2023, and particularly following the escalation of the war in Lebanon in the past few months, these forces have been under pressure due to near-daily Israeli strikes on Iranian and Hizbollah targets in Syria. Together, these developments have meant that the government’s foreign allies, which had safeguarded its survival for the past decade, are either weakened or preoccupied elsewhere.
Aleppo was also something of a soft target. Rebel elements originally took over parts of the city in 2012. Since 2016, when the Syrian army and allied militias recaptured Aleppo with Russian and Iranian support, the government has done little to bolster the city’s defences. Pro-government forces remained fragmented, with militias in particular pursuing pecuniary gain rather than building the government’s military capabilities. The army and affiliated militias did not have a joint operations room during the rebel offensive, which left them fighting independently, exposing their poor coordination in the face of the rebel forces’ new tactics.
What explains the government’s ineffective response?
Clearly diminished support from Hizbollah, other Iran-backed groups and Russia, which has given only limited air support, has mattered. Most of all, though, the rebel offensive exposed vulnerabilities in government defences, which collapsed all along the front, with soldiers and other pro-government forces fleeing rather than putting up a fight. With little integration between infantry and artillery units, not to speak of the air force, the army had little close-range fire support. Mobile HTS assault teams exploited these gaps to overwhelm defensive positions. The rout in Aleppo was particularly shocking, given that during the war to date the government has been bent on holding major cities at any cost. Despite the defender’s advantages in urban terrain and the arrival of reinforcements, such as the army’s 25th Division and the Republican Guard, Syrian forces barely defended strategic positions, including the Citadel, the medieval fort on a hill overlooking the city. (During the 2016 fighting, the Citadel was a crucial defensive point for government forces even when rebels controlled much of eastern Aleppo.)
Despite having expected some form of rebel offensive for months, Damascus was caught off guard by the rebels’ swift progress. Alongside Russia, it had been conducting pre-emptive airstrikes on HTS-controlled territory in Idlib and neighbouring areas since October in an attempt to deter a rebel attack. These efforts were clearly in vain. Since the offensive began in late November, pro-government forces have been withdrawing from most of Aleppo provinceand areas in eastern and southern Idlib to southern Aleppo province and Hama province, allowing rebels, who faced little resistance, to seize areas like Aleppo city, Saraqib and Maarat al-Numan. The rebel advances indicate the direction of travel – Damascus – and inevitably raise the question of whether the government will have the capacity to reinforce its combat units and muster resources for a counteroffensive.
Who is fighting?
Pro-government forces are both Syrian and foreign. They include the army’s 25th Division, the Republican Guard, the army’s 5th Corps; paramilitary units such as the National Defence Forces, Liwa al-Quds and Local Defence Forces; militias affiliated with the Syrian Social Nationalist Party and the Baath Party; the locally important al-Berri clan militia; and Iran-backed groups such as the al-Abbas Brigade. Other Iran-backed groups from outside Syria, including the Afghan Fatemiyoun Brigade and the Pakistani Zainebiyoun Brigade, bolster pro-government ranks.
Most of the foreign fighters in government-held areas belong to Iraqi groups such as Harakat al-Nujaba, Kata’ib Sayed al-Shuhada and Kata’ib Hizbollah. They add fighting strength, but they lack the skill that Hizbollah exhibited. Most are stationed close to the Iraqi border, but some have redeployed in support of government forces. Harakat al-Nujaba, for example, which had been around Aleppo, has withdrawn to Hama, a city roughly half the way to Damascus on the M5 highway, to strengthen defensive lines there. Kata’ib Sayed al-Shuhada has reportedly sent additional fighters into Syria, awaiting coordination with Iran and the Syrian government before determining where to deploy. Kata’ib Hizbollah is still reading the landscape, waiting to decide whether to enter the fighting.
Fragmentation has repeatedly hindered the [Syrian] government’s ability to coordinate responses to rebel offensives.
In this array of forces, a central weakness is the lack of unified command. Fragmentation has repeatedly hindered the government’s ability to coordinate responses to rebel offensives. During the 2016 battle for Aleppo, rebels were able to exploit pro-government forces’ disorganisation at first. While the latter eventually prevailed, the rebels initially routed government forces, which suffered territorial losses and high fatalities, similar to those in late November, although on a smaller scale. In the current fighting, the 25th Division has led limited counterattacks, but the absence of a cohesive command structure continues to obstruct decision-making and operational efficiency.
The Syrian Defence Forces (SDF), mostly Kurdish units that hold much of the country’s north east, add a layer of complexity to the situation. The government has often fought the SDF, but it now appears to have struck a tactical deal with the group to defend what is left of the Aleppo districts it recaptured in 2016. Before retreating, government forces handed over areas including Deir Hafer, Maskana, Sheikh Najjar and the international airport to the SDF. Simultaneously, Russia has been aiding the SDF in warding off threats to their domain in the north east from Turkish-backed factions, as Russian airstrikes have hit those factions’ positions in al-Bab and Marea, areas in northern Aleppo province adjacent to SDF-held territory. But whether the SDF can hang on to these areas, which are isolated from its north-eastern strongholds, in the face of the swift rebel advances is uncertain at best.
On the rebel side, apart from HTS, the strongest group, there are several factions. The most structured, such as Ahrar al-Sham and Faylaq al-Sham, both of which are Islamist, and smaller non-ideological groups, are in Idlib province. They fight alongside HTS under a unified Military Operations Command. They are joined by the SNA, which includes a range of groups, some of which previously formed the bulk of the Free Syrian Army in areas under Turkish control in the northern Aleppo countryside and Afrin. While they all want to remove the Assad government, they are divided by ideology, personality conflicts and (sometimes) outside support, although HTS has used its dominance in Idlib province since 2019 to curb cross-factional competition there.
What could come next?
While HTS is trying to solidify control of areas it has seized, pro-government forces are regrouping in and around Hama, which has remained under government control throughout the war. Losing Hama would open the door for the rebels to push farther south, fundamentally altering the war’s trajectory and maybe even threatening the government’s survival. If the government’s defences at Hama hold, the area would likely become the launchpad for its counteroffensive toward Aleppo’s countryside, as it has been in the past, particularly if Iran-backed groups or Russia weigh in more forcefully. Major reinforcements have arrived in the city. If government forces can prepare to push outward from Hama, the question will be what sort of resistance rebels can put up.
The rebel advances are likely to push Damascus closer to Iran and Hizbollah, thus blocking – at least for now – any pathway the Syrian leadership might have had to distance itself from Iran’s axis. Since Syria’s readmittance into the Arab League in May 2023, Damascus has been improving diplomatic ties and discussed economic cooperation with the United Arab Emirates in particular, though the outcome of these discussions remains to be seen. Gulf Arab states have held out economic incentives – which might require them to circumvent U.S. sanctions on Syria – but they would want to see Damascus limit Iranian influence. That now seems an unlikely prospect, given events. In any case, Syria had shown little sign of compromise even before this latest offensive. The extent of any renewed government effort at strengthening the alignment with Iran will depend on whether pro-government forces can quickly halt the rebel advance. If the government succeeds in doing that, with Russian support, it may avoid having to deepen its reliance on Tehran.
As in 2015, when the tide of Syria’s war turned in the government’s favour, Russian support could prove a game changer. Though it has staged several airstrikes during the rebel offensive, Russia’s engagement thus far appears lower than it did prior to the Ukraine war. To compensate for the reduced Russian air support, the government has been firing tactical missiles at HTS command posts and logistical nodes, to little avail. If Russia were to ramp up its involvement, it could slow, halt or even reverse rebel gains. Additional Russian equipment is expected to arrive soon. Civilian flights from the Russian air base at Hmeimem are being diverted to Damascus to make room for more military traffic. In addition to bombing the front lines, Russia will likely aim to destabilise rebel-held areas by targeting civilian sites, making them much more difficult to govern, as well as causing civilian casualties and renewed mass displacement.
Fighting could also escalate between the rebels and Kurdish-led forces.
Meanwhile, fighting could also escalate between the rebels and Kurdish-led forces. The People’s Protection Units (YPG) – the SDF’s backbone that is linked to the Kurdistan Workers Party (PKK) in Türkiye – have controlled pockets of Aleppo and the surrounding countryside for years. One flashpoint is Tel Rifaat, a town north of Aleppo. The YPG captured it from rebel forces in 2016 and has subsequently used it as a staging ground for attacks on Turkish forces. Media outlets reported on 1 December that Ankara-backed rebels had driven the YPG out of Tel Rifaat. Another is Sheikh Maqsoud, an Aleppo neighbourhood with a significant Kurdish population. (In a statement, HTS offered the SDF safe passage out of Aleppo, promising not to harm the city’s Kurdish civilians; tactical deals between HTS and the SDF are also not out of the question.)
Much will also depend on how effectively the rebels govern newly captured territory, assuming they hold it – particularly since Aleppo has a bigger, more diverse population than other areas in their hands. HTS established a governance body in Idlib, known as the Syrian Salvation Government, some years back; it is a rival of the Syrian Interim Government that administers other opposition-held areas in cooperation with Türkiye. As the leading force in the offensive, HTS could put in place a formula in Aleppo that incorporates other political and civil society figures. Senior HTS leaders tell Crisis Group that the group is considering appointing such a body, distinct from governance arrangements in Idlib. That might make its rule more palatable for both the local population and outside powers that have kept HTS at arm’s length. It could mitigate the implications of HTS’s terrorist designation, allow in foreign aid and help facilitate IDP returns.
The Salvation Government has asked Idlib-based NGOs, including international ones, to move to Aleppo, and its ministry of development and humanitarian affairs announced plans to open an office in the city on 2 December. It reportedly has also established checkpoints in the city and restored electricity. The group also emphasised its commitment to safeguarding foreign consulates and protecting religious minorities. Still, HTS’s history and ideological roots mean it will struggle to address many Syrians’ concerns about living under its rule and the implications for their personal and religious freedoms.
What are the implications of these events for the various actors involved?
For the Syrian government, the loss of Aleppo to the rebels is a major blow. Aleppo is not just a big city; it is a symbol of the government’s victory in the civil war, with its recapture in 2016 serving as a defining triumph for Damascus and its allies. Losing it now upends that narrative: the government will now have more difficulty casting itself as capable of holding onto Syria’s heartland without heavy reliance on foreign support. To the contrary, Aleppo’s rapid fall reinforces perceptions that the government’s survival hinges on Iranian and Russian backing. With this setback, Damascus may lose credibility among countries seeking to normalise relations, such as Gulf Arab states. That said, the opposite may also occur: the UAE and Jordan, which fear the prospect of Islamists seizing power in Syria, have spoken up in support of the government. Thus far, events appear to have reinforced rather than reduced their motivation to forge ties with Damascus anew.
For HTS, military success also changes the prevailing narrative. It is no longer a force hidden away in a corner of Syria, largely unnoticed by the outside world. The fact that HTS – a group designated a terrorist organisation by the UN, the U.S., the EU and Türkiye – ruled Idlib and its environs was not particularly objectionable abroad. Now that could change, and HTS will face a real challenge. Its rule in Aleppo cannot be a mirror image of how it has governed Idlib, given Aleppo’s size and the diversity of its population. Syrians will watch closely. Will there be chaos? Can HTS be more inclusive of other groups and of minorities? If it fails, it will be judged harshly. If it succeeds, other countries, including in Europe, may start feeling pressure to deal directly with HTS.
For Russia, Syria had been a success story, a demonstration of its ability to influence events in the Middle East. Moscow has invested significant time and effort in Syria since 2015, and it will therefore do what it can to prevent the government’s collapse. Amid the war in Ukraine, defeat in Syria or even wider rebel gains would be a blow to the Kremlin’s credibility and a victory for its adversaries. The offensive has thus opened a new front for Russia, one that will demand additional weapons and resources. But the war in Ukraine complicates any move to resupply by sea, as Türkiye is blocking Russian warships from transiting the Bosphorus and Dardanelles (under Article 19 of the Montreux Convention, which stipulates that during a war in which Türkiye is not involved, warships of the belligerent parties are prohibited from using these maritime channels except when returning to base). Moscow and Ankara could wind up at loggerheads. If, as Russian media outlets suggest, Russia concludes that Türkiye is backing efforts to put the government in Damascus on the back foot, it may seek to strike deep within rebel-held areas to trigger new waves of refugees heading toward the Turkish border.
As for Türkiye, fearing just such a scenario, it had reportedly urged rebels, including HTS, not to launch an offensive, in large part because it feared that Russian-backed retaliatory strikes could send hundreds of thousands of Syrians toward the Turkish border. Turkish officials say HTS had signalled to Ankara that it would respond to the uptick in strikes by pro-government forces in Idlib. They also say Ankara had raised the issue with Russia and Iran. Neither, however, was inclined to rein in pro-government forces. Still, if Ankara knew a rebel offensive might be on the cards, it does not appear to have explicitly greenlit the campaign and, in any case, it probably could not have anticipated such rapid opposition gains; indeed, even the HTS leadership probably did not foresee such a rapid retreat by pro-government forces.
Ankara may now feel that Assad could be more inclined to negotiate with the opposition for a lasting settlement of the Syria quagmire.
At the same time, Türkiye could benefit from the rebel’s offensive. The expansion of their area of control would enlarge Ankara’s sphere of influence at the expense of an Assad government backed by Moscow and Tehran, with which it competes for regional influence. Moreover, Ankara may hope that expanded rebel control of the north could open opportunities to send back Syrian refugees currently in Türkiye. Importantly, Syria-Türkiye rapprochement talks have stalled. Ankara may now feel that Assad could be more inclined to negotiate with the opposition for a lasting settlement of the Syria quagmire.
The SDF/YPG has reason to be concerned, because Türkiye and the Türkiye-backed rebels – and to a lesser extent HTS – see the group as aligned with Damascus. Ankara cites evidence from the past few days, and stretching back to the civil war’s onset, that government forces arranged with the YPG to occupy areas they had vacated due to the need to deploy elsewhere. The understanding has invariably been that the YPG would be a temporary custodian; the authorities in Damascus are adamantly opposed to any notion of Kurdish autonomy. Türkiye – in conjunction with the SNA – may see an opportunity to push back the YPG from areas it holds in northern Syria based on its view that the YPG is a branch of the PKK, which it has designated a terrorist organisation.
In Tehran, events in Syria are cause for significant alarm. Speaking with his Syrian counterpart as rebel forces gained ground in Aleppo (killing an Islamic Revolutionary Guard Corps general), Abbas Araghchi, Iran’s Foreign Minister, framed the offensive as part of a U.S.-Israeli plot. He pledged Tehran’s support for an ally on whose survival it has already expended significant blood and treasure. The Islamic Republic is keen not only to preserve the Assad government, one of its few allies, but to maintain a conduit for transferring military assistance to Hizbollah, whose need for that aid has become more dire. If Damascus’s grip starts slipping in places beyond Aleppo, and rebel gains disrupt the Iranian arms pipeline to Hizbollah (which Israel already strikes frequently), Tehran would likely feel it has to jump into the breach. Still, at a time when its vulnerabilities have been laid bare on several fronts, including on its home soil, and given the loss of several Revolutionary Guard commanders in the area, Tehran would have to grapple with whether and how to prevent the fall of a pivotal ally in its “forward defence” strategy on a front that until recently seemed assured.
For Hizbollah, the offensive’s implications appear limited for now. The group remains focused on its war with Israel and had already withdrawn most of its fighters from north-western Syria. But if the Syrian rebels advance further in Hama, the group’s logistics routes could come under threat, posing challenges to its operations in the longer term. It would seek to reverse the situation in close cooperation with Iran.
Washington seems to prefer staying on the sidelines.
Finally, Washington seems to prefer staying on the sidelines – and not just because of the pending change in presidential administrations. The administration is concerned about developments that could trigger widespread civilian suffering and broader regional instability. The potential use of chemical weapons by an Assad government pushed further on the defensive is also on the administration’s radar. Still, the U.S. has higher priorities than Syria in the Middle East. As a U.S. official noted, “What’s happening is not about us”. Moreover, despite its longstanding opposition to the Assad government and its earlier involvement backing rebel groups during the Syrian civil war, the Biden administration is wary of HTS, which remains a U.S.-designated terrorist group. As such, the Biden administration does not believe it has obvious policy options for advancing its interests.
Nonetheless, the U.S. has been in communication with Ankara about potential lines of conflict between Turkish-backed rebel groups and the SDF, which could upset longstanding U.S.-backed arrangements in north-eastern Syria. Further Turkish-backed advances against the SDF could prompt calls for the U.S. to become more actively involved to protect its Kurdish partners. The U.S. has emphasised that it is prepared to “defend and protect” its personnel and assets in Syria, where around 900 U.S. forces are deployed, as part of its counter-ISIS mission.