The so-called Islamic State (IS) used to control 88,000 sq km of territory in Syria and Iraq and had imposed its control on around eight million people. IS as a caliphate made its last stand in the besieged Syrian village of Baghuz on the eastern bank of the Euphrates River and ultimately collapsed on March 23, 2019. The international community has been celebrating the terrorist group’s military defeat; the end of a war that lasted four and a half years. The fight against IS costed thousands of lives including many civilians, extensive destruction and billions of dollars. The IS self-declared caliphate has come to an end, however the group is far from finished and will most likely continue to constitute a destabilising factor in Syria and the broader Middle East. It still poses a global terrorist threat as well.
Retreat to the rural areas
Since IS lost the city Mosul in July 2017, it gradually withdrew to loosely controlled deserts and plains of Syria and Iraq where it still has thousands of fighters and sympathisers. IS militants have mainly retreated to the vastly Syrian Desert (Bādiyat Al-Shām) between Homs, Dier Al Zor and Al-Sweida governorates, and to a lesser extent in Idlib and adjacent opposition-held areas.
IS’s strategic retreat to remote areas signals its transformation and the return to its terrorist roots. Even though IS uses terrorism as a tactic, it should no longer be identified merely as an insurgent group. Insurgent groups control territory and population, exercise sovereignty over them while having the ability to engage in conventional military operations. On the other hand, terrorist groups do not in principle seek to control territory and use terrorism as a tool against militarily superior enemies. When a terrorist group becomes militarily capable, it usually shifts to an insurgent group.
The strategic retreat to the deserts/remote areas is undoubtedly a sign of military defeat, the loss of its so-called caliphate and therefore a decision to preserve its manpower and focus on conducting guerilla warfare. Having lost the territory it once controlled, the pursuing of guerilla warfare has remained its only option left to sustain its cause. The next step would be to attempt to exploit favourable conditions for a comeback. IS’s guerilla warfare in Syrian deserts/plains involves targeted assassinations, kidnappings, planting of roadside bombs-IED (Improvised Explosive Devices), ambushes as well as hit-and-run attacks against the Syrian Arab Army and Syrian Democratic Forces (SDF) checkpoints that lie on the edge of desert cities (Al-Sukhnah, Dier Al Zor, Mayadin, Al-Bukamal).
Through guerilla warfare, IS has reached its full potential and current capabilities, as the attacks are conducted by small, independent, battle-hardened, but also ideologically-motivated IS fighters. IS fighters use the dark of night and dust storms to surprise their enemies, undermine the enemy’s morale and consequently its fighting strength. Guerilla warfare allows keeping the enemy occupied and challenging the Syrian government/SDF authorities over the affected areas. In this case, it creates dissatisfaction to locals allied with the aforementioned authorities and undermine reconstruction efforts.
On the other hand, IS attacks might backfire and turn some locals against it. Despite this, IS can demonstrate to its domestic as well as worldwide supporters that it is still alive. Although degraded, it is still surviving and fighting a holy war against an “infidel”, “apostate” regime and “atheist”, “communist” militias respectively. Guerilla warfare also helps IS to demonstrate that the struggle for the creation of a pure Islamic caliphate has not ended and that its quest will prevail in the end. In other words, it will continue to be a magnet for mostly local extremist and replenish its ranks.
Furthermore, the geomorphological features of the Syrian deserts constitute another obstacle to anti-IS forces in their effort to sustain an effective counterinsurgency. Syrian deserts cover extensive areas that make it almost impossible for security forces to establish effective control, giving IS cells relative freedom of movement. Moreover, IS has taken advantage of Badiya Al-Sham’s various caves and rugged hills to create many underground hideouts to avoid airstrikes and surveillance operations.
Repeated attempts against the terrorist group have not managed to uproot it from the region. A well-planned and extensive military operation by President Assad’s forces cannot occur as long as a considerable number of his beleaguered troops are concentrated around the heavily armed opposition (of around 30,000) held areas in the northwestern of the country. The loose control of the Syrian Desert is due to remain even after a future large-scale military operation, unless the fate of rebel- and SDF-held Syria were be determined. Here it must be remembered that Al-Qaeda adopted a similar strategy when it retreated to the deserts of Anbar Province in western Iraq following its defeat from Sunni Arab tribes backed by the US.
The SDF and Turkish threats
The SDF currently control nearly one-third of Syria and possess a strong force of 60,000 to 75,000 fighters. Following IS’s defeat in Baghuz, the SDF focused their operations on rooting out IS cells from their controlled region. Nevertheless, Turkish threats and military preparations for an invasion in the city of Manbij and the areas on the eastern bank of the Euphrates forced the SDF to place their forces on high alert and to deploy more troops in the Syrian-Turkish border.
The YPG defeat in Afrin remains fresh in the mind of Syrian Kurds. Amid Turkey’s threats, the SDF vowed and are “obliged” to fight to death to preserve their de-facto autonomous region or at least some of their gains in post-war Syria. At a time when the SDF is trying to establish security in eastern Syria, they have to consolidate their positions at the Turkey-Syria border and be prepared for a Turkish invasion. As such, the SDF were forced to disrupt their operations on two fronts and this by extension weakened their effectiveness against IS sleeper cells.
If Turkey carries out its threats of an invasion, IS cells in the urban areas of Raqqa, Manbij and others can also intensify their attacks against the SDF and disrupt their efforts to confront Turkish forces and proxy attacks. Regarding Syrian deserts, IS cells might take advantage of the chaos, power vacuum and lack of security to regain territory and create the conditions for an IS resurgence. The long distance between a hypothetical SDF-Turkish front near the border and a second one in the desert region near the Syrian-Iraqi border will likely add additional difficulties to SDF control over northeast Syria.
Most importantly, a Turkish invasion can lead to a temporary pause of SDF counterterrorism operations against ISIS. It should be pointed out that SDF briefly suspended their operations against IS when Turkey attacked SDF along the Syrian-Turkish border at the end of 2018.
Turkish threats are not the only reason preserving IS presence in Syria. Internal divisions within the SDF have also played a role. According to Al-Monitor, Arab tribal leaders whose forces are part of SDF and fought alongside the Kurdish YPG against IS, “have been reaching out to the Assad regime and cutting individual deals”. Arab tribal leaders’ efforts to reproach Assad have intensified since President Trump’s announcement on the withdrawal of the US military forces from Syria. Tensions are not new within the SDF, though the common threat against IS and the US support have served as a uniting factor between Kurds and Arabs. Tensions have flared between Kurds and Arabs in the past when the latter vehemently opposed with protests to forcible recruitment into the ranks of SDF among others. The uncertainty over the future of northern Syria will likely increase these divisions with IS trying to take advantage of local tensions and disagreements either militarily or by bringing into the surface ethnic/social strife between Kurds and Arabs.
Arab resentment within SDF, combined with high casualties, constitute another restrictive factor for an effective counterinsurgency against IS cells. The prolonged war against IS has taken a heavy toll on SDF, causing 11,000 losses. The Kurdish YPG, being the main fighting force of the SDF, cannot underestimate and ignore the need of preserving Arab units in the SDF ranks and the de-facto political institutions of northern Syria. The stabilisation of the region, the need to portray themselves as a multi-ethnic political structure vis-à-vis the West and Turkey, but also the demographics of the area necessitate the existence of local Sunni Arab forces and their political representatives.
IS’s most potent weapon remains its ideology
Kinetic warfare against IS proved partially effective as it caused the gradual disbanding of the group, inner disunity among its members and forced its leadership to go underground. However, the terrorist group ideology is still alive, as well as its ability to inspire radicalised individuals across the globe. Western efforts largely failed to counter the IS ideological framework, as the group achieved to recruit about 20,000 fighters including many from Western nations.
IS will most probably be able to survive and attract new recruits, even if most of its influential leadership has been killed. As an illustration of this, attention should be given to the Islamic State of Iraq (ISI). Back in 2010, ISI (an Al-Qaeda offshoot in Iraq) lost most of its leaders and was near collapse. In a press conference on June 4, 2010, US commander in Iraq, General Ray Odierno mentioned: “Over the last 90 days or so, we’ve either picked up or killed 34 out of the top 42 Al-Qaeda in Iraq leaders.” Among those killed were two of its most senior leadership: AQI emir Abu Omar al-Baghdadi and war minister Abu Ayyub al-Masri.
However, ISI had managed to survive and replenish its leadership, with Abu Bakr al-Baghdadi emerging as the new leader of the Sunni militant group. Baghdadi later broke with ISI and renamed his group with the well-known ‘The Islamic State in Iraq and the Levant’ (ISIS) in 2013 and as ‘Islamic State’ (IS) in 2014. Given the example of ISI, the killing of IS leadership will most likely be ineffective. This demonstrates that this ideology helped the extremist group’s predecessor to maintain its relevance. Ideology motivates, not only new recruits but also IS remnants to continue the insurgency, even with fewer resources and no substantial territory under their control. In other words, ideologies are not defeated with weapons and ideological battles can also take decades to be successful.
Furthermore, a whole generation of Syrian and Iraqi children have been raised under IS rule. IS has trained and embodied its toxic ideology to children through the absolute control of education in each piece of territory fallen under their control. Children have been taught a strict interpretation of Islam (Salafi-jihadism). They have been recruited as child soldiers and used as suicide bombers, among others. Their vulnerability and trauma have deteriorated further, especially because of their arrest and torture for alleged IS affiliation, as well as due to the killing or detention of their parents.
The example of Iraq indicates essential implications for the future of IS in Syria. “This is a generation that will grow up into something worse than Isis […] But nobody cares”, said Bushra al-Obaidy, a human rights lawyer who has been appointed to head an Iraqi government committee on ISIS families. In a similar context, “this humiliating collective punishment risks laying the foundation for future violence” said Lynn Maalouf, Amnesty International’s Middle East Research Director. If Syrian authorities do not take the necessary de-radicalisation and re-integration measures, these children will possibly pose a future threat, not only to Syria but also against regional and Western countries. The rehabilitation and integration of those children back into societies are fundamental to prevent the next generation of terrorists.
As the Syrian conflict has already entered its 9th year, President Assad has strengthened his grip on power. The primary causes/conditions that fuelled the resurgence of IS have not resolved yet but remain unchanged and even in a worse situation than the early stages of the conflict. Following successful military achievements, President Assad is more hesitant than ever before to make any compromise. The staunch refusal of President Assad for a political settlement and a power-sharing model of governance that would address the socio-political and identity roots of Syrian conflict much favours the resurgence of the jihadist cause. Specifically, political stability and security cannot be achieved without addressing the Sunni and broader social disappointment. Otherwise, IS will be able to exploit the frustration of Sunnis, who consider Assad their primary cause of hardships. In turn, this may help replenish their ranks and thereby sustain the insurgency.
Another example can be found in the history of the Syrian Muslim Brotherhood. Hafez Al Assad, the former Syrian President and Bashar’s father, has long fought to destroy the Syrian branch of the Muslim Brotherhood. Hafez Al Assad crackdown on Syria’s Muslim Brotherhood and Islamist insurgency during the 1970s-1980s led to thousands of deaths. The government offensive against the Muslim Brotherhood revolt in Hama resulted in around 10,000 to 30,000 deaths. Many of the current Islamist rebel groups’ ideological successors can be traced back in the failed Muslim Brotherhood uprising. As the ongoing conflict has already claimed more than half a million lives and millions of displacements, it can be assumed that at least a low-level insurgency will continue, unless a political transformation and a long-term reconciliation plan are implemented.
Furthermore, Russia and Iran do not alone possess the financial means to rebuild Syria and revive its devastated economy. In this case, it is possible that Western and other countries that oppose Assad will assurances for political reforms and reconciliation measures to financially contribute to the post-war reconstruction of the country. If Assad remains unwilling to make any compromise, the majority of the western world might not support Syria. At this point, the reconciliation of some countries with Damascus and President Assad is not enough to provide any tangible economic benefits. Without economic recovery/development, political stability, reconstruction, and an increase in employment opportunities, it will not be difficult for IS to tap into a new pool of potential supporters to fight against a President who they consider as the main reason of their political, social and economic vulnerability.
The weakening and sidelining of the Syrian opposition
There are clear domestic and external causes that led to Assad’s survival and the defeat of the Syrian opposition. The Russian military intervention in Syria (2015), opposition infighting, disagreements among its sponsor states and others have led to Syrian rebel defeat. Syrian Islamists rebels associated with the Turkish-backed National Liberation Front (NLF) suffered a massive blow after Hayat Tahrir Al-Sham (Al Qaeda’s Syrian branch) took over most of rebel-held Idlib and the adjacent opposition-held parts of western Aleppo and northern Hama. In specific, the Free Syrian Army’s Nour al-din al-Zenki Movement (currently part of NLF) had almost dissolved by HTS and sought refuge to the Turkish controlled areas of northern Aleppo. In another case, FSA’s Southern Front defeat and the loss of Deraa (the birthplace of Syrian uprising) to the Syrian army and its allies, marked one of the most prominent signals of rebel’s imminent defeat both symbolically as well as militarily.
The weakening and sidelining of Islamists and other less hard-line opposition forces such as Ahrar Al-Sham, Faylaq al-Sham (military wing of Syrian Muslim Brotherhood) and Jaish Al-Islam have only benefited IS but also Hayat Tahrir Al-Sham (HTS) and other Al-Qaeda linked forces as they marked the end of the revolution. With the weakening of mainstream Syrian opposition forces, IS and HTS have become the only capable and committed forces with the power to inflict considerable cost on Assad’s forces and disrupt their efforts to stabilise the whole of the country and bring it under his rule.
For this reason, Syrians who are opposed to Assad and are inclined to continue the insurgency against his regime will be left with no other alternative but to join forces with the jihadists. IS and HTS, though rivals, can be presented as the only anti-Assad forces who have managed to survive through the prolonged conflict. In this regard, IS and HTS will not find it difficult to attract new recruits among dissatisfied and severely affected Sunni Syrians.
IS’s military defeat in Syria has brought about signs of a likely stabilisation of the country. Nevertheless, the Assad and SDF victories do not necessarily mean the end of IS’s presence and jihadist extremism in the country. Idlib has been transformed into a hub for Al-Qaeda-linked jihadists. If the international community does not resolve the causal problems that fuelled the rise of IS, they will possibly face its resurgence or other similar groups in the future, which are likely to be more violent than their predecessor.
By Michalis Foulias
 US, Turkey and SDF have been negotiating for the creation of a buffer zone over the past couple of months. In the case of an agreement, a Turkish military operation will possibly have less destructive consequences.
 Kurdish forces have approached Assad to discuss the post-war status on northeast Syria. Syrian Kurds have also sought Assad’s support during the ‘Operation Olive Branch’ in Afrin and asked for Syrian army deployment in Manbij area to avert a Turkish military operation.
 Kinetic warfare against IS has involved, among other things, an excessive air campaign against IS oil facilities, armored vehicles as well as its military personnel and leadership. Kinetic warfare is defined as “the ability to create effects that rely on explosives or physical momentum (i.e., of, or relating to, or produced by motion)” and “Non-Kinetic Means” as “the ability to create effects that do not rely on explosives or physical momentum (e.g., directed energy, computer viruses/hacking, chemical, and biological) “‘suggested by the former US Deputy’s Advisory Working Group (DAWG)