Syrian regime fighter jets launched aerial attacks yesterday on key positions held by the Islamic State of Iraq and Syria (ISIS) in the eastern Syrian city of Raqqa, and Qaim, across the Iraqi border. The strikes are part of the Syrian government’s intensified campaign against ISIS, which has been using the spoils from its takeover of Mosul earlier this month to propel its expansion in Syria.

The attack surprised those who assumed that Assad, who has until now been fairly passive in fighting ISIS in the east, would focus on the war’s other fronts while letting armed groups fight among – and ultimately weaken – themselves. But as reports emerged that ISIS has been gaining recruits from Jabhat al-Nusra and other extremist groups, concern spread in Damascus that its power could grow faster than expected – possibly requiring intervention.

The decision to hit Qaim is a strategic one, says Theodore Karasik, director of research and development at the Institute for Near East and Gulf Military Analysis (INEGMA) in Dubai. “That’s the heart of ISIS’s caliphate [in Anbar province]. The other, in Raqqa, was because it’s the major hub and supply chain for ISIS in Syria.”

Here, Karasik, Yezid Sayigh, senior associate at the Carnegie Middle East Center, and Chris Phillips, lecturer at the University of London and former Syria editor at the Economist Intelligence Unit, explain why the regime chose to attack sooner than expected, and debate whether its involvement in the fight against ISIS is symbolic – or the start of a new front in Syria.

Syria Deeply: Why did the regime choose to strike now?

Theodore Karasik: Syria struck these targets because they recognize the threat that the group poses as it swings back towards Syria. Damascus wants to interrupt ISIS’s push back west, because you see that as they go, supply lines are interrupted – and all that ISIS captured in Iraq can not only be used in [fighting that] may be coming up in Baghdad and Jordan, but also back into Syria. Therefore, you have this response. On top of that you have what seems to be some coordination between Syria and Iran on what to do with what’s happening in Iraq. Iran is nervous about an ISIS swing-back as well.

Yesterday there was some reporting from the Syrian Observatory for Human Rights that said parts of Nusra are declaring [allegiance] to ISIS. I don’t really buy it, but I do buy the concept of it. I think ISIS’s advance in Iraq is going to draw a lot of followers to them from other extremist groups, and that’s another reason why Damascus is concerned. If elements of Nusra and other Islamist groups begin to join ISIS in a dignified manner, they will become a more formidable force.

Yezid Sayigh: It seems clear enough that this is entirely linked to developments this month in Iraq. The regime hadn’t bothered to make an effort against the rebels generally in the east – any of them – and so this is almost certainly connected to the events in Iraq, and there of course because the regime sees a growing threat to its own position, in Deir Ezzor in particular, where ISIS has taken over the province from other rebel groups. Or it’s because the regime wants to look like it’s part of the fight against ISIS. It’s probably a bit of all of these things.

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.