" “ISIS’ main objective is to end the existence of the FSA, and attack Arsal,” the source said. “It might not have won the battle of Arsal, but ISIS worked and is succeeding in weakening the FSA in some areas.”
After suffering major losses in Iraq’s Tikrit, the bulk of ISIS fighters in Qalamoun have withdrawn to Syrian territories following instructions from senior command. What was originally a fighting force of approximately 2,000 militants has been reduced to 400-450, the source said.
“That is why remnants of this battalion are putting the fight on the FSA, to force them to push allegiance, corner them or make them settle with casualties to reduce pressure on their forces on the eastern side of Qalamoun,” explained Mario Abou Zeid of the Carnegie Middle East Center.
ISIS’ focus on the FSA during the current battle is also “an indicator of how much the Syrian regime is deeply connected to and interacting with ISIS,” he added.
According to sources in Qalamoun, this relationship is also reflected in how ISIS receives its supplies, which must cross regime checkpoints on its way from Raqqa."