The sudden downfall of Bashar Al-Assad has raised a number of questions about the thinking and roles of his supporters. First and foremost, Russia—the most powerful foreign ally of the Syrian government—played a pivotal role as events unfolded.

According to one high-ranking regional diplomatic source, Assad’s recent visit to Moscow was a turning point. While the Syrian leader was in Russia, forces led by the Sunni Islamist Hayat Tahrir Al-Sham (HTS) unexpectedly seized Aleppo without a fight. Upon his return to Syria, Assad is said to have expressed anger toward his army. In private meetings, Amwaj.media has learned, he lambasted his...