There is a consensus that the regime of Syrian President Bashar al-Assad is on the strategic defensive, and many anticipate that the rebels opposing him will make significant new gains in coming months. The regime still has sufficient military capability to defend its core areas, but the real risk to it comes from the difficulty of maintaining the morale and political cohesion of those who fight for it. In a period of high volatility, this could trigger the regime’s unravelling sooner than expected. If it survives, which remains the most likely, then Syria will return to strategic stalemate, albeit along new frontlines. These do not presage formal partition, but if the de facto division of territory stabilizes it will form the basis for any deal the principal external actors involved in the armed conflict might reach to end it.

Any changes to the map of Syria’s conflict in the rest of 2015 will almost certainly occur in what now constitutes Syria’s “shatterbelt:” those areas caught between the main combatants—the regime, armed opposition, and Islamic State—where they will conduct their main battles and where they may gain or cede territory without this resulting in complete victory or defeat for any of them. The shatterbelt comprises regime-held areas of Daraa city and other parts of Syria’s south, Aleppo city and its nearby countryside, and the region east of the Damascus-Homs highway where the Islamic State poses a looming threat.

Yezid Sayigh Yezid Sayigh is a senior fellow at the Carnegie Middle East Center in Beirut, where he leads the program on Civil-Military Relations in Arab States (CMRAS). His work focuses on the comparative political and economic roles of Arab armed forces and nonstate actors, the impact of war on states and societies, and the politics of postconflict reconstruction and security sector transformation in Arab transitions, and authoritarian resurgence. More >

The regime is visibly preparing itself for the loss of parts or all of the shatterbelt, by reinforcing and preparing new defensive positions along a contracted frontline. In the south, opposition reports show that it has been pulling heavy armour and artillery back towards Damascus for some time; its new line is likely to center on Kisweh, which has been a hub of Syrian defences facing Israel for decades. Homs has been key to regime combat operations during the ongoing conflict, and is now emerging as the central hub of its future defence plans. Foreign sources with good connections to the army report that construction is underway in one or more of the major air bases east of Homs to house troops, which reveals that the regime anticipates the need for a new, long-term defence line there.

The regime enclave in Daraa city is most vulnerable, although the armed opposition is currently focusing on Quneitra and the western approaches to Damascus, while seeking to neutralize the Druze-inhabited Soueida province politically. However, the governments represented in the joint Military Operations Center in Amman appear especially concerned to regulate the pace of military developments in the south: they do not wish the regime to unravel precipitately and offer the Islamic State an opportunity to access Damascus. For now the Southern Front, which groups the “moderate” rebels supported by the Military Operations Center, is largely biding its time and focusing instead on preparing for the aftermath of a regime retreat or downfall.

The regime can afford to abandon Daraa, but Aleppo poses a much bigger dilemma. Many talk of Aleppo as if its fall in the hands of the rebels is relatively easy or imminent. But this seems unlikely. Regime forces could hold out for a long while in the city and its surrounding countryside, which international relief organizations believe contain several million people. Although some parts of the city face a severe shortage of water, it generally has some ability to withstand a cut-off of its main supply by using boreholes; even regime-held neighborhoods only receive one to two hours of electricity a day, and so further cuts would add to the population’s misery but not prove decisive. And despite the likelihood that international relief convoys will no longer be able to reach Aleppo from Damascus, the city gets most of its food supply locally. The ability of much smaller opposition areas to endure protracted sieges—such as al-Wa’ar in Homs—shows how long they can endure.

Furthermore, maintaining its Aleppo enclave has come at relatively low cost for the regime: its defence there is mainly conducted by local urban Sunni militias and clans in the southern countryside, while foreign Shia militiamen have borne much of the burden of offensive operations to the north since late 2014; the regime has not had to invest major army manpower. Indeed the city is a net asset: the civilian population supplements government salaries and subsidies with remittances from family members abroad, providing the regime with an income stream. Abandoning Aleppo would mean a loss of income, though the real cost would be political as the regime’s claim to represent all Syrians including a great many Sunnis would be gravely weakened. But because Aleppo is not vital to the regime’s strategic defence, the regime could still decide to transfer its army garrison to reinforce the frontline in more critical areas, not least in the eastern and northern Hama countryside against the Islamic State and armed opposition respectively.

However, the real threat to the regime’s strategic position is the vulnerability of the Damascus-Homs highway. The recent loss of Palmyra means this is the only road connecting the two cities to each other and to the coastal region beyond that remains under regime control. It is essential for the regime to hold it, but the highway is now exposed to attack by the Islamic State, which would additionally place it in close proximity to the Lebanese border facing the northern Beqaa Valley. This explains ongoing Hizbullah operations to clear the western Qalamoun area, which provides strategic depth parallel to the highway. The challenge for the Syrian army is gaining defensive depth to the east: it already has major bases to the east of Homs going towards Palmyra, but the zone south of this line is neither populated nor fortified.

The Damascus-Homs highway is not part of Syria’s shatterbelt, since the regime cannot afford to cede territory here, but it may witness a constant game of cat and mouse between regime forces and the Islamic State. What helps the regime is that although its adversary has continued to gain and train new recruits, it is unlikely to have accumulated enough manpower to wrest a permanent foothold in this area. But merely demonstrating its ability to pose a real threat serves the Islamic State’s purpose and keeps the regime on the defensive.

In the meantime, the Islamic State will maintain its pressure on the last regime pockets in Deir al-Zor city, which presents a more valuable prize, by consolidating Islamic State control over the entire province. The regime has invested considerably in maintaining its enclave there, but may soon face an agonizing choice. It could try to pull out its army garrison, but this is a difficult, if not impossible task since the Islamic State controls all roads around for hundreds of kilometres and could make an air evacuation highly dangerous; a pull-out would moreover mean leaving thousands of local militiamen, officials, and state employees and some 250,000 civilians to the mercy of the Islamic State. But equally the regime cannot risk seeing its garrison suffer the fate of the hundreds of soldiers who were summarily executed when the Islamic State overran the Tabqa base in August 2014, which would inflict severe damage on the morale and loyalty of regime constituencies.

The regime will be most vulnerable if its supporters perceive that its end has come, a perception it may seek to dispel by arguing that a political deal is in the offing that will reflect its ability to retain its core areas, or what al-Assad called “useful” Syria. No less importantly, recent announcements by the Turkish and Jordanian governments that they are hosting record numbers of Syrian refugees may signal a reluctance to back major new offensives by the rebels they support that could propel massive new waves of refugees into their territories. If Syria’s shatterbelt holds, then the conflict will settle into stalemate once more.

This article was originally published in Arabic by Al-Hayat.