Rapid rebel advances in northern Syria will expand the civil war into further factionalism, threaten Iranian supply lines to Lebanon, and eventually destabilize the Syrian government by exacerbating its economic and security challenges. On Nov. 30, the Syrian rebel group Hayat Tahrir al-Sham claimed control of Syria's second-largest city, Aleppo, in a lightning advance against Syrian government forces. The insurgents and other associated militias continued their advance southward toward the Syrian city of Hama while also consolidating control of much of northern Syria, including taking territories previously held by Kurdish forces as part of the Syrian Democratic Forces. By Dec. 2, Syrian forces had dug in around Hama in an attempt to halt further rebel advances. Meanwhile, Russia increased the scale of its air campaign against Hayat Tahrir al-Sham fighters now entrenched in Aleppo. Fighting also broke out elsewhere in the country, including in Damascus and Suwayda, though as of...
