On Wednesday, Syrian rebels shocked the world with a surprise offensive against President Bashar al-Assad's forces in northern Syria. In a swift operation lasting under 72 hours, they seized significant portions of Aleppo, the nation’s second-largest city, which had taken regime forces over four years to reclaim.

Employing tactics painfully familiar to Israelis - rocket assaults, drone strikes, and rapid incursions from concealed positions—the rebels managed to outmaneuver the Russian and Syrian air forces that dominate the skies. The attack was a remarkable success, catching the Syrian army and its allies, including Iranian militias and Russian troops, off guard. Footage of the rebels celebrating their triumph, capturing prisoners, seizing abandoned weapons, and chanting religious slogans circulated widely.

But who are these rebels, and how did they emerge after years of the Syrian conflict fading from view? The answer is intricate, reflecting the complex political landscape of the uprising. Broadly, the rebel forces can be categorized into two main factions.

The first is the group known as Hay’at Tahrir al-Sham (HTS), an extremist Islamist organization with roots in al-Qaeda operatives who joined the anti-Assad movement at its inception. 

Led by Abu Muhammad al-Julani, the group has become the dominant force among Syrian rebels and was instrumental in orchestrating the northern offensive.

Tahrir al-Sham has spent over two years preparing for this assault, engaging in extensive training reportedly funded by Persian Gulf states, while building underground command networks and stockpiling weapons and ammunition sourced from Turkey. The organization’s members, many with ties to former al-Qaeda and ISIS factions, have maintained a hardline stance, with some openly displaying the Islamic State flag.

The second group spearheading the northern attack consists of various factions under the umbrella of the "Syrian National Army," which receives direct military support from Turkey.

These groups range from moderate nationalists to more radical Islamist factions. It’s noteworthy that cooperation among the National Army’s members is not always smooth; in recent months, some factions have even clashed with one another.

While only one of these factions has direct ties to Turkey, both groups rely significantly on the Turkish military presence in northern Syria. This support has helped stabilize the front lines between 2017 and 2018, preventing the capture of Idlib province—the last major area held by rebel forces. Idlib has turned into a chaotic environment, where the Turkish lira circulates and countless refugees endure dire living conditions. 

From this region, which spans much of northern Syria, the rebels have long strategized for a counteroffensive to reclaim their homeland. A confluence of Turkey’s desire for retribution against Moscow and the weakening of the Iranian axis, exacerbated by setbacks for Hezbollah in Lebanon, has transformed meticulous planning into a scenario ripe for action.