Chris Phillips: There has been a lot of press coverage of the regime's role in ISIS coming [to power]. It had a desire for radicalism to emerge – in order to discredit the opposition – but it doesn't actually want ISIS to thrive. It doesn't mean they want them to succeed in taking very large swaths of Syria and Iraq – and I suspect they've been genuinely shocked by the capacity ISIS has shown in the last few weeks. While they were content with ISIS controlling parts of eastern Syria, they now see a force that could control parts of Iraq as well – so the regime could be genuinely concerned about ISIS's momentum and trying to check it.
There's also the matter of its ally, Iran, which has contributed a large amount to the regime's war effort and is now sending its own troops to take on ISIS in Iraq. So for it to request [aerial] help from the Syrian government is not out of the question.
Syria Deeply: The regime's military resources are stretched. Does it have the manpower to fully tackle ISIS?
Karasik: Syria is augmented by fighters from Hezbollah and Iran's Revolutionary Guard Corps (IRGC). By now they're battle-hardened and will be able to fight against any kind of unified ISIS umbrella, if one does appear. So I think it's possible we'll see a massive fight in Syria between these forces.
Sayigh: I don't think they will engage in a full-on fight with ISIS. What they're doing is sending some aircraft up – that's a cheap form of response. It's more symbolic than effective. It's clear that as in Iraq, putting up air strikes against a likely armed enemy or one that is based in urban areas is really ineffective. The regime is stretched enough as it is in core areas like Damascus, which it cares about more. It isn't going to send troops out to the east. It has no interest in the eastern area, except in relation to maintaining a presence in the city centers of Deir Ezzor, Qamishli and Hassakeh. It is not willing to invest major resources in order to open up big fronts there.
So it's not going to change strategy. Sending air strikes is for show. It's unlikely to have any kind of significant material impact. And therefore it's much more about appearance, about demonstrating that it's on the same side [against ISIS] as the U.S. and everyone else.
Phillips: The regime's position hasn't changed. It doesn't have the capacity to reconquer all of Syria. What it seems to want to do is keep the opposition factions, including ISIS, [contained] and fighting each other.
The regime is also attacking ISIS symbolically. The regime's long-term plan, remember, is to risk short-term international isolation, then wait for the international climate to shift and walk back in. It might see ISIS as that opportunity. If it can present itself as the force in the region that the West can count on to take on ISIS, then its period of international isolation would end.