The fallout from Israel’s war with Hamas and Hezbollah has triggered a domino effect threatening Syrian President Bashar Assad’s grip on power and Iran’s regional influence.

A surprise offensive by the Sunni jihadist group Hay’at Tahrir al-Sham (HTS), affiliated with al-Qaeda, is reshaping the battlefield and delivering devastating losses to Syrian government forces backed by Iran and Russia.

This rapid escalation began shortly after an Israeli-Hezbollah ceasefire went into effect on Wednesday morning. Hezbollah has been badly weakened by the war, unable to assist Assad’s forces in the face of the HTS offensive.  Israel confirmed eliminating 2,500 Hezbollah terrorists and likely killed at least 1,000 more. Casualties include nearly all of the terror group’s top leadership. Israeli forces also seized 25,000 weapons.

By Wednesday, Hay’at Tahrir al-Sham — formerly known as the Nusra Front — launched a surprise attack on Aleppo, Syria’s industrial and economic hub, marking the largest assault on Assad’s forces in the region since 2020. The rebels have since captured the international airport and seized control of over 75% of Aleppo’s neighborhoods.

HTS rapidly advanced into the northwest Syrian city of Idlib and are now threatening Hama, overwhelming Assad’s army, which has struggled to mount an effective defense. Over 330 casualties have been reported, including Hajj Hashem, a senior Iranian advisor, and Ahmad Ali, the Syrian security chief in Aleppo. Iranian-backed positions and infrastructure, including the consulate in Aleppo, have been severely hit.

Iran’s dual crises—protecting Hezbollah and shoring up Assad—have left it vulnerable on multiple fronts. Tehran accused the U.S. and Israel of orchestrating the Syrian attacks, labeling them part of a broader campaign to destabilize the region. Iranian Foreign Minister Abbas Araqchi is set to visit Damascus for urgent talks with Assad, following consultations with Turkey and Russia.

Turkey’s alleged support for HTS further complicated the situation. While Ankara has a history of backing opposition groups against Assad, it also faces tensions with Kurdish forces, who have surprisingly aligned with Assad to counter the rebel offensive.

Russia, which also backs Assad, launched airstrikes against the HTS, but with Moscow preoccupied with its war in Ukraine, may not be able to do much more.