The Motivations Behind the "Sectarian Killings" in Syria

Gunfire erupts in a crowded street as masked men in the back of a military truck unleash a barrage of bullets. In another video circulating on Syrian social media, apartment buildings — reportedly home to Alawite families — are engulfed in flames within seconds, their windows flashing as the fire takes hold.

Elsewhere, a man wearing military fatigues and riding a motorcycle pulls up to a house and orders the resident to face the camera before executing him. Another harrowing clip of film captures a lifeless body sprawled on open ground as a voice sneers, “These are the Alawite pigs,” before firing again.

The wave of brutal attacks comes as Syria faces its deadliest unrest since the fall of dictator Bashar al-Assad in December. The violence erupted on Thursday after reports surfaced that loyalists to Mr. Assad carried out a series of coordinated attacks, ambushing and killing at least 200 members of Hayat Tahrir al-Sham, the rebel group that led his ousting.

But there is more to what happened, and the forces behind it, than meets the eye.