As the world's media focus on the Gaza conflict, Syria has just had the bloodiest week of its civil war. Some 1,700 people have been killed in seven days, with a renewed push by Islamic State (IS) forces accounting for much of the violence. Confident after its victories in Iraq and using newly looted military hardware, IS's sudden charge and the reaction to it in Syria and outside have tilted the conflict on its axis, challenging assumptions and shifting dynamics. Increasingly, we can talk about a war being fought on four overlapping fronts by four different actors: the Al-Assad government, IS, mainstream rebels and Kurds. The first front is between IS and Syrian President Bashar Al-Assad's government. Al-Assad facilitated IS's rise by cynically releasing jihadists from prison, in order to radicalise the opposition, and then deliberately avoiding military confrontation. The sudden and terrifying upsurge in IS actions has only helped Al-Assad. IS alarmed the west, prompting some to suggest that a rapprochement with Damascus is the least bad option; it terrified Al-Assad's own population, reinforcing the government's message that it is their only defence; and it physically attacked Al-Assad's enemies among the mainstream rebels while avoiding battle with the government's troops. Any implicit alliance was shattered this month, however, when IS stormed three separate government targets in the cities of Homs, Raqqa and Hassakeh, killing hundreds of government troops, then gruesomely videoing their severed heads impaled on spikes. Such heavy losses have rocked Al-Assad's domestic supporters, provoking rare outrage and criticism on social media. Most accept the government's characterisation of the opposition as sectarian jihadists and many, especially Syria's Alawites, have sent thousands to die in battle against them. IS seems the most brutal of all, particularly to another core constituent, Syria's Christians, who have been shocked by the recent expulsion of their co-religionists from Mosul. These defeats show the government's inability to actually defend its supporters. Al-Assad's forces are actually weaker as a result of the IS attack in Iraq, as many of the Iraqi Shiite militia who had fought for him have now returned to defend their homes. But Al-Assad cannot afford to isolate his base, and a more concerted campaign against IS can be expected, stretching his resources even thinner. This was seen already when one IS-captured area, the Shaar gas field in Homs, was retaken. Al-Assad also misread Syria's second front: the war between IS and the mainstream rebels. He assumed that IS would finish off the weakened rebels before redirecting their war against him. True, IS has recently conquered many rebel territories, pushing the Al-Nusra Front out of Deir Al-Zur and making inroads into the Aleppo countryside, but it is no longer playing Al-Assad's game. As IS expands and occupies more land, it requires more troops and an acquiescent local population. While it still seeks military victories over rival rebel groups, it also wants to woo their fighters. Similarly, it is making more efforts to win hearts and minds in the regions it conquers. Turning its guns on Al-Assad's forces achieves both goals: countering any former accusations that it was the government's ally and presenting itself as the best route to its overthrow. On the other side, the mainstream rebels seem as divided as ever. While they temporarily united to push IS out of the north in January, the various militias and fiefdoms continue to compete for territory and resources. The Washington Post has noted how the US's closest ally, the Harakat Hazm group, clashed with another group, Ahrar Al-Sham, over control of the Bab Al-Hawa border crossing last week. Despite western attempts to paint these rebels as “moderate” the reality is that most are, more accurately “non-IS Islamists”, with the Al-Nusra Front being an Al-Qaeda affiliate. Given how fluid allegiance to the rebel militias has been, there is a real chance that idealistic young fighters impressed by IS's momentum could peel away. This is increasingly likely as the rebels face defeat in Syria's third front: the war between themselves and Al-Assad. Ignoring IS, Al-Assad has focused on recapturing Aleppo. He has replicated the brutal tactics used to recapture Homs in March: depopulating hostile districts with barrel bombs before moving in to clear out the remaining rebel fighters. Retaking Syria's second city would allow Al-Assad to declare the war won, even if much of rural Syria remains outside of his control, and it would certainly cripple the rebels. This decline and IS's surge have created a new urgency in Washington, and the familiar calls to “arm the rebels” have been heard again, with some proposing that the rebels be trained to simultaneously resist Al-Assad and IS. However, this is unrealistic. IS defeated Iraq's national army within days, and there is no evidence to suggest that an uncoordinated collection of feuding militia could suddenly overcome three years of disunity to do better. Even if they could unite, the resources proposed are too few. US President Barack Obama has authorised US$500 million to train and arm the rebels, but this won't appear until 2015 and the covert weaponry delivered so far is restricted to eight small, carefully vetted groups, resulting in a limited impact. Moreover, after the MH17 plane disaster in Ukraine, there is even less appetite in the White House to deliver the shoulder-launched anti-aircraft missiles (known as Manpads, from the acronym for man-portable air-defence systems) that the hawks demand. More positively, after three years of backing rival rebel groups, Turkey, Saudi Arabia and Qatar seem to have been sobered by IS's dramatic battlefield successes, and stronger coordination may follow. These efforts may prove enough to keep the mainstream rebels in the field, probably around Deraa and Idleb, and may even prevent large numbers of fighters switching to IS. But it is unlikely that they can form a realistic rival to IS; the increased support will probably come too late to prevent Al-Assad's march on Aleppo. Changes have also come on Syria's fourth, and least-reported, front: the battle between IS and Syria's Kurdish militia. Kurdish militias, led by the PYD — the Syrian wing of the Kurdish People's Party (PKK) — have used the Syrian civil war to carve out autonomous regions, clashing with IS in the process. July saw intense fighting over the PYD-controlled border town of Ain Al-Arab/Kobani, prompting a radical new position by Turkey. Fearful of Kurdish nationalism, Turkey had previously opposed the PYD, closing its border to prevent any support from the PKK. It allegedly turned a blind eye to those supporting IS. However, the shift of IS forces into Iraq has prompted a U-turn. With Ankara now realising the severity of the IS threat and fearful that Ain Al-Arab would give it a launchpad into Turkey, the border was opened, prompting a stream of 1,000 PKK fighters into Syria to help the PYD hold off the IS advance. While Kurdish-IS clashes will likely continue, the emergence of a united PYD-PKK military force is a new dynamic. Ironically, it may provide Turkey with a much-needed buffer against IS, but it also increases the likelihood that an autonomous Kurdish Syrian region will one day become a reality. Despite these changing dynamics, none of the four forces looks likely to win outright. Al-Assad might take Aleppo but he will face increased public pressure to take on IS, stretching his limited military resources. The mainstream rebels may be facing imminent defeat but they probably have enough external support to remain in the field. Syria's Kurds now have PKK support but that remains vulnerable to Turkish border policy. Even IS, seemingly in the ascendency, must manage the shift from invader to occupier and win over enough fighters and civilians to continue its march west. Regardless of how IS's recent charge has shifted, dissolved or solidified the Syrian civil war's fronts and actors, its presence in the battlefield seems more likely to perpetuate the conflict rather than hurry its end. The writer is a lecturer at Queen Mary, University of London, and associate fellow of the Middle East and North Africa Programme at Chatham House.
