The proxy war in Syria was never about an internal insurgency. Saudi Arabia and Israel both wanted Assad gone for different reasons, but worked together to accomplish the goal. We armed the rebels to include ISIS to help them accomplish the goal. The “evil” Russians stopped that plan.
Israeli TV recently reported concerns about the advances of the Syrian Army in the east of Syria, particularly in relation to the breaking of the ISIS sign on Deir ez-Zor ,an ISIS stronghold for around four years. Israeli analysts were shown watching reports on the victory of President Assad and the Syrian Army in Deir ez-Zor as they broke the siege and starting liberating more territory from ISIS. Read more here.