On December 4, 2024, rebel forces led by Hay’at Tahrir al-Sham (HTS) under the leadership of Abu Mohammad al-Jolani seized control of Aleppo, marking a dramatic shift in the Syrian conflict. The group swiftly expanded its territory, capturing Hama and Homs, and advancing toward Damascus. As a result, Bashar al-Assad, the longest-surviving leader of the Arab Spring, was forced to flee the country. In response, the Syrian Prime Minister pledged to cooperate with HTS’s leader.
Assad’s brutal regime has been responsible for the deaths of hundreds of thousands of Syrians and the displacement of millions. Since the outbreak of the civil war in 2011, Syria has witnessed the rise of ISIS’s de facto government, the emergence of various ISIS and Al-Qaeda-affiliated groups, and the involvement of Turkish-backed rebel forces. HTS now stands as one of the last remaining major rebel forces in the conflict, alongside other groups still vying for control in different parts of the country.
The Global Terrorism and Trends Analysis Center (GTTAC) Records of Incidents Database (GRID) reported that between January 1, 2018, and December 1, 2024, 88 terrorist perpetrators were responsible for 7,960 attacks in Syria. These incidents resulted in 17,132 deaths, including 2,066 perpetrators, and left 13,703 people injured and 1,072 kidnapped. Additionally, eight U.S. citizens were killed, and 58 others were injured during this period. Figure 1 below shows the number of attacks and fatalities over this time. The number of incidents fluctuated between 2020 and 2024, with a noticeable increase in 2022 and 2023. GTTAC’s data entry is ongoing, and the number of incidents in 2024 is expected to be similar to previous years.
Figure 2 below shows the number of perpetrators killed during the same period, which can indicate a terrorist group’s capacity. A smaller number of perpetrators killed, while inflicting a higher number of casualties, may suggest the group’s growing effectiveness. In 2020, 884 perpetrators were killed in Syria, but this number sharply decreased in the following years, despite the high volume of attacks. This shift could indicate two things: either the groups’ capabilities have increased, or the Assad regime and its allies have become less effective in responding to these groups.
Since the onset of the Syrian civil war, the country has become a battleground for multiple global powers, each with their own strategic interests. The United States supported Kurdish forces in northern Syria, who were considered the most reliable partners in the fight against ISIS and Al-Qaeda. Meanwhile, Turkiye backed so-called moderate forces to prevent Kurdish groups from expanding along the Mediterranean coast. Iran continued its historical support for Bashar al-Assad, as Assad’s father was the only Arab leader to support Iran during its war with Iraq in the 1980s. Iran saw Assad as a loyal ally, preferring his regime over a potential Sunni government that might align with Gulf states like Saudi Arabia. Russia’s primary goal was to maintain its military base in Tartus on the Mediterranean, which could only be preserved by keeping Assad in power.
HTS is the successor to Jabhat al-Nusra, which was originally affiliated with Al-Qaeda in Syria. Al-Nusra was responsible for numerous terrorist attacks in Syria, including the 2016 assassination of the Russian Ambassador to Turkiye. Since 2017, HTS has attempted to distance itself from Al-Qaeda by rebranding, aiming to gain both local and international support. Although HTS’s leader deliberately severed ties with Al-Qaeda to avoid being targeted by the U.S., the group still maintains strong ideological and organizational connections with Al-Qaeda in Afghanistan. Many of HTS’s fighters have been trained in Al-Qaeda camps, and the group continues to share Al-Qaeda’s salafi-jihadist ideology.
GTTAC data reveals fluctuating numbers of HTS attacks in Syria. While the group’s attacks increased steadily in 2022 and 2023, they declined in 2024, as shown in Figure 3. This decline suggests that HTS may have intentionally kept a low profile to avoid drawing attention before executing its takeover strategy.
The Syrian National Army (SNA), the second major rebel force under HTS’s leadership, is supported by Turkiye. Established in 2017, the SNA is an umbrella group of various Syrian rebel factions, including former Free Syrian Army (FSA) groups and other opposition forces that align with Turkiye’s interests. The SNA primarily operates in northern Syria, where it has fought against both Kurdish forces and Syrian government troops. Turkiye backs the SNA as part of its broader strategy to counter Kurdish militias, which it sees as a threat due to their connections with the PKK (Kurdistan Workers’ Party). In return, the SNA receives military resources, training, and strategic support from Turkiye, strengthening its role in the Syrian conflict.
According to GRID data, the SNA has carried out numerous attacks targeting Kurdish forces, foreign military personnel, and Syrian government troops. Like HTS, the SNA has sought to maintain a low profile while serving Turkiye’s interests. Since 2019, the SNA has been responsible for dozens of attacks. In 2024 alone, the group conducted 22 attacks, resulting in 23 deaths.
Several factors were critical in the unprecedented control gained by HTS-led rebel forces in Syria. HTS’s strategy of withdrawing to Idlib and reorganizing its forces proved to be a pivotal move. By retreating to this relatively isolated region, HTS has regrouped, restructured, and strengthened its military presence without drawing immediate attention from major international players. Meanwhile, ISIS, considered the primary security threat, became the focal point of U.S. military efforts. U.S.-backed Kurdish forces, along with American airstrikes, focused on targeting ISIS fighters and their leadership, which led to the elimination of three successive ISIS leaders. This diversion allowed HTS to rebuild and expand its influence, taking advantage of the shift in attention.
HTS’s relationship with Turkiye played a key role in sustaining its strength. Turkiye provided logistical support to HTS through border crossings. Idlib, HTS’s stronghold, borders Turkiye, which allowed the group to receive fighters, weapons, and supplies with relative ease. Additionally, Turkish-backed groups in the region indirectly supported HTS, creating a broader network of rebel forces aligned with Turkish interests. Meanwhile, regional shifts further contributed to HTS’s rise. Iran’s support for its allied militias in Syria began to decline after the October 7 attacks, which led to major losses for Iran-backed groups, including Hezbollah. This weakening of Iran’s position in Syria allowed HTS and other rebel groups to capitalize on the power vacuum. Similarly, Russia’s involvement in the war in Ukraine strained its ability to support Assad, weakening its commitment to Syria. Internal weaknesses within the Assad regime, such as corruption and inefficiency, further exacerbated the situation, creating opportunities for rebel forces to exploit these vulnerabilities and expand their control across Syria.
There has been ongoing uncertainty about whether HTS-led forces can maintain power and survive in the long term. It is still too early to predict how regional actors will respond or whether they will support an HTS-led government in the region. The area has already experienced the rule of ISIS, which established a de facto government but failed to govern effectively. Under ISIS leadership, people were subjected to harsh repression. The group imposed a strict and violent interpretation of Sharia law, which included public executions, amputations, and other brutal punishments for perceived transgressions. Freedom of expression was severely restricted, and anyone suspected of opposing ISIS faced violent repercussions. The group also enforced strict dress codes, particularly for women, and severely curtailed basic freedoms, such as access to education, healthcare, and employment, especially for women and minorities. ISIS’s so-called “caliphate” was marked by a culture of fear and intimidation rather than governance. Like ISIS, HTS-led forces also lack the capacity to govern appropriately. Their leadership and organization are not equipped to run a country. Given this, it seems inevitable that the region will experience looting and instability as rebel forces take control.
The United States has maintained a presence in the region primarily due to the rising threat of jihadist terrorism. Moving forward, the U.S. will closely monitor the activities of HTS-led forces, especially to assess any potential links to ISIS or Al-Qaeda. The U.S. is particularly concerned about the possibility of HTS adopting similar extremist ideologies or tactics, which could further destabilize the region. At the same time, the weakening influence of Iran and Russia in Syria—both of which have been critical supporters of the Assad regime—could create a shift in the balance of power. This loss of influence might present new opportunities for the U.S. to pursue its regional strategic objectives, such as limiting Iran’s reach and curbing Russia’s influence.
Lessons for counterterrorism policies can be drawn from the effectiveness of terrorism in the region. While many terrorist organizations throughout history have failed to achieve their ultimate goals, despite claiming that terrorism is a successful strategy, recent events offer a different perspective. The Taliban’s takeover of Afghanistan, after two decades of fighting against the U.S.-backed Afghan government, shows that terrorism can sometimes achieve its objectives. This suggests that the Taliban’s success has inspired other jihadist groups. Similarly, the growing influence of HTS indicates that terrorism could also be an effective means of achieving their goals. Salafi-jihadist groups in regions such as Nigeria, Somalia, the Sahel, Afghanistan, and Pakistan might now see these successes as proof that their struggles could eventually lead to victory.
Another key lesson is the unpredictability of global conflicts. The Israeli government failed to anticipate the October 7 terror attacks, in which Hamas killed over 1,300 Israeli civilians. In response, Israel’s overreaction resulted in the deaths of more than 45,000 Palestinians. Beyond the staggering loss of life, these events have further deepened regional conflicts, isolated Israel diplomatically, and created a persistent fear of future Hamas attacks. Similarly, counterterrorism strategies have failed to foresee the rise in HTS’s capabilities and leadership, which ultimately enabled the group to take control of Syria.
Finally, the fall of authoritarian regimes offers an important lesson. Bashar al-Assad now joins the ranks of toppled Middle Eastern leaders like Saddam Hussein, Muammar Qaddafi, and Hosni Mubarak. These autocrats, who once enjoyed lavish lifestyles, could not escape the consequences of repressing and displacing their own people. Their regimes eventually crumbled when they failed to meet the needs of their citizens.
The current winners of the Syrian civil war appear to be HTS, the rebel forces, and Turkiye. Turkiye has been cautious in its relationship with HTS, given the group’s Al-Qaeda affiliations, but has supported anti-Assad forces, portraying them as “moderates” or legitimate opposition. The Turkish government is likely to use the situation to highlight the success of its regional strategy, positioning it as a victory in the face of Turkiye’s current economic challenges. The government may also frame the situation as a potential solution to the issue of over six million Syrian refugees in Turkiye, promising that they could soon return home, easing tensions within the country.
However, while the current situation seems to benefit Turkiye, its ties to Hamas and other jihadist groups in the region could pose risks in the future. Turkiye’s continued support for such groups could create diplomatic challenges and tensions with other regional powers. The balance Turkiye seeks between maintaining its alliances, advancing its security interests, and addressing domestic issues will shape its future policies in Syria and the broader region. While Turkiye may enjoy short-term gains, the long-term implications of its associations with these groups remain uncertain, and the evolving dynamics of the conflict could introduce unforeseen challenges.
To conclude, HTS’s success has led to the downfall of the last surviving leader of the Arab Spring, Bashar al-Assad. This highlights how terrorism can be an effective strategy for achieving political objectives in the region, and it may inspire other jihadist groups in the Middle East and Africa. However, it remains unclear how HTS’s leadership will address the needs of the Syrian population, which is deeply divided and fraught with animosity. Furthermore, HTS’s leadership capabilities are limited, as demonstrated by the failure of ISIS to govern effectively in the region. Given its strategic interests in the region, Turkiye will play a crucial role in influencing HTS’s future actions. With Assad’s departure, Russia and Iran are likely to lose their influence in Syria. The United States will continue to monitor the evolving situation, focusing on the relationship between HTS and Al-Qaeda. This development raises concerns that Al-Qaeda could establish a second safe haven in Syria, in addition to the Taliban-controlled government in Afghanistan.
Click here to read Mahmut Cengiz’s previous article on the growing strength of rebel forces in Syria.