The dynamics driving this in Iraq are fundamentally indigenous to Iraqi domestic politics. This is still a group that within Syria has a broad array of factions aligned against it. ISIS is not an organization that's going to galvanize Assad ad-hoc partnerships with opposition groups in Syria. But you have enough of an array of players that have an interest in stifling the development of ISIS, minimizing its influence, so I don't see this as an immediate threat [to the balance of power in Syria.]
Kirk Sowell: ISIS has been moving weapons and equipment from Mosul back to Syria. As far as ISIS is concerned, it's going to weaken them in the long term. They're engaging in direct fighting with the Iraqi army, and the Iraqi army is not going to lose these fights. In Tal Afar this week, ISIS was initially able to gain some ground there because it's out in the west, harder to resupply. But after the government sent more units out, they were able to regain the initiative. ISIS has around 10,000 fighters, and the Iraqi army still has 200,000. ISIS doesn't have an unlimited supply of personnel, so these direct fights – like in Tal Afar – just drain them.
Syria has a much greater impact on Iraq than Iraq has on Syria. Having this rear base in Raqqa has been great for ISIS – it's what allowed them to organize and recruit and train their fighters. If you take parts of Anbar and Nineveh, in Iraq, and Deir Ezzor and Raqqa and parts of Hassakeh, in Syria, that's the so-called Islamic state. But these aren't areas they totally control, and once Baghdad sends high-quality [military] units up to Mosul, ISIS is not going to be able to hold its ground or form an administration or anything like that.
Syria Deeply: If ISIS is able to topple Maliki, what would that mean for Assad?
Ted Karasik: Maliki's fight for maintaining his government is significant in the fact that it's a Shiite government, and in Syria, there is an Alawite government, which is a branch of Shiism. If ISIS continues with these successes and is able to oust Maliki, it will probably see another opportunity to push hard against Assad. ISIS would feel emboldened to go back to Syria – and it would better know what to do there in order to topple Assad, because of lessons learned in Iraq.
Syria Deeply: How does Assad see what's been happening in Iraq?
Riedel: The Assad regime sees [the ISIS offensive] as the perfect bogeyman that undermines the legitimate opposition. Assad now nicely has those rebels caught in a vice between him and his Iranian allies and associates like Hezbollah, and on the other side, ISIS. So he's probably quite comfortable with what's happened [in the last two weeks].
Karasik: The only scenario I see is something discussed a while ago about the "red-line" chemical weapons issue, where the U.S. and its allies were planning to bomb Syrian military infrastructure in surgical strikes. But part of the plan was to go after ISIS at that time, and they never did. If they had done so, we might not be facing this situation today. Not a lot of people realized that part of the air plan was to go after ISIS at the same time.