ISTANBUL, Turkey—On Sunday afternoon, a video depicting a large convoy of Islamist Syrian rebel fighters yelling enthusiastically as they drove off to war circulated widely on Arabic social media. Fighters in the packed trucks, driving quickly past the group of children filming with their phones, could be heard yelling “Allahu Akbar!” and, “Our leader, 'til the end of time, is our master, Muhammad!”However, what shocked those watching the video weren’t the shouts of the Syrian fighters but rather those of the children filming, who yelled back at the soldiers in a language unfamiliar to most Syrians following their country’s nine-year war. “That’s not Kurdish, right?” said one user in an online group where the video emerged. “If they were Kurds, you think they’d be cheering them on?” responded another with a laugh out loud emoji.Over the next several hours, rumors swirled that the video was shot in Azerbaijan, a small Turkic-speaking nation lodged between Iran and Russia, and that t
