The bombing last Wednesday in Damascus of President Bashar Assad’s national security headquarters, the most significant blow yet to the Assad regime, was perpetrated by an Islamist group and not the Free Syrian Army, as was initially claimed, according to an Israeli expert on Arab affairs.

This achievement, by a local radical group, will carry significance in the sectarian struggle for power that is sure to come in the wake of Assad’s departure, said Dr. Mordechai Kedar, an expert on Arab affairs at Bar-Ilan University.

The July 18 blast killed Defense Minister Daoud Rajha, the highest ranking Christian in the regime; Assef Shawkat, the president’s brother-in-law and deputy commander of the military; Hassan Turkmani, military adviser to the foreign minister; and Hisham Ikhtiyar, the national security chief. The four were an instrumental part of the regime’s brutal efforts to extinguish the 17-month-old uprising in Syria. The blow, in the heart of Damascus, appears to have hastened the end of Assad’s rule.

If Assad’s Alawite sect, considered infidels by Sunni Muslims, withdraws from Damascus and hunkers down in western Syria where it holds a majority — west of the Orantes River and between Latakia in the north and Tartus in the south — and the non-Arab Kurds break off into their own mini-state, as they have done in Iraq, then the remaining Druze, Christian, Sunni and Salafist sects will battle for what remains, Kedar said. In light of this possibility, the identity of last week’s attackers is highly significant.

“The video of the attack is absolutely replete with Islamist messages,” said Kedar. By contrast, the Free Syrian Army, he noted, has always gone out of its way to avoid any sort of Islamist affiliation, trying to rally all of Syria’s sects and religions against the regime.

Speaking of the icon in the top left-hand corner of the video clip, Kedar noted that it features green flags with white writing, the colors of Islam, and the verses quoted on them are from the Shahada, the Muslim prayer and profession of faith. The writing on the icon in red says “al-Haq,” which means, literally, “the truth” but is one of the 99 descriptive names for Allah, and the entire icon is cradled by a green crescent. The music accompanying the blast, is an Islamic chant, and the sermon, delivered toward the end of the clip, is directed at Satan. In Syria today, Kedar said, that means Assad.

Nor was the footage randomly captured by an Islamist group. Kedar, a former military intelligence officer, said the camera was intentionally positioned one kilometer away from the site of the explosion, in the national security agency building.

Kedar explained that he established the distance based on the three-second gap between the sight of the explosion and the sound of the blast, taking into account that sound travels roughly 300 meters a second, and on the stability of the frame, which does not move. He said that the camera had been perfectly positioned, the focus crisp.

“The people who filmed that footage knew in advance. They set up the camera, arranged the focus,” Kedar said. “They were part of the cell of attackers and not just up on a rooftop by chance.”