Challenging the Yemeni State: ISIS in Aden and al Mukalla

ISIS is prosecuting a campaign in Yemen designed to elevate its position on the global stage and compete with one of al Qaeda’s strongest affiliates. ISIS will likely surge in Yemen during Ramadan 2016 and attempt to derail ongoing efforts to bring stability and security to southern Yemen.

The Islamic State of Iraq and al Sham (ISIS) operates in Yemen in support of its global campaign to expand the Caliphate. Yemen is a key theater for the Salafi-jihadi movement because of its religious significance and location on the Arabian Peninsula. Al Qaeda has operated there since the early 1990s, using the country as a logistics and planning hub for international operations, establishing a base from which to attack the House of Saud, and setting conditions for the creation of a Muslim army.[1] ISIS seeks to compete directly with al Qaeda in Yemen, particularly al Qaeda in the Arabian Peninsula (AQAP), to suppress the Yemeni state, to expand the regional sectarian war, and to disrupt Saudi Arabia by both inspiring attacks within the country and threatening the Gulf nation from multiple sides.[2] It is actively challenging the reconstitution of the Yemeni state in southern Yemen, which also supports its narrative campaign to contest AQAP’s dominance over the Salafi-jihadi movement in Yemen.

ISIS’s Wilayats in Yemen

The ISIS base in Yemen remains limited to small cells in 2016 after an initial burst of support in the spring and summer of 2015.  There are at least eight ISIS wilayats, provinces, in Yemen that have claimed attacks since that time, though only a handful of them have sustained regular attacks into 2016 and are currently active.[3] ISIS Wilayat Sana’a, which conducted multiple coordinated attacks against alleged Zaydi Shi’a mosques in the capital in 2015, has not claimed a major attack in 2016, for instance.[4] Many of the ISIS wilayats in Yemen were in all likelihood originally AQAP cells that switched allegiance. ISIS’s reputation for victory, its higher pay, and the instant global ISIS community probably attracted the initial recruits in 2015.[5]

The attraction of ISIS in Yemen declined by the end of 2015, though a successful ISIS campaign in summer 2016 could again capture potential recruits from AQAP. Recruitment declined, in part, due to ISIS no longer paying its fighters significantly more than AQAP and due to growing discontent among the ranks with ISIS local leadership.[6] Over 100 ISIS members publicly called for the dismissal of the ISIS wali, governor, in Yemen in two letters in mid-December 2015.[7] They listed concerns of excesses and shari’a violations and disavowed the wali. The ISIS wali in Yemen is a Saudi, as are many of the higher-ranking ISIS leaders in Yemen, which also likely drove friction with the local Yemeni cells. The overall tempo of ISIS attacks in Yemen decreased as support declined, but the active ISIS wilayats continued to attack in Aden and Hadramawt. 

ISIS’s Campaign in Yemen

ISIS has shifted its attack pattern as it progresses in its Yemen campaign and exploits shifting circumstances in Yemen’s civil war. The majority of ISIS’s attacks in Yemen during the first half of 2015 targeted the al Houthis, who are Zaydi Shi’a and who claimed control of the Yemeni government in Sana’a. Many of the now-inactive wilayats had conducted low-level attacks against al Houthi forces across the country, and ISIS Wilayat Sana’a prosecuted a campaign of spectacular attacks against alleged al Houthi mosques in the capital city.[8] ISIS’s primary objective was to exacerbate sectarian tensions in Yemen’s civil war, which had divided the country roughly along sectarian lines, though the population mobilized for political, not religious, reasons.[9] The targeting of Shi'a in Yemen also nested into a global ISIS sectarian campaign. The Saudi-led coalition’s ground invasion in July 2015 re-established the internationally recognized Yemeni government’s presence in Yemen and gave ISIS the opportunity to shift to attacks against the Yemeni government and Saudi-led coalition forces. ISIS is deliberately shaping two similar campaigns in the southern port cities that will challenge the reconstitution of the Yemeni central government.

ISIS’s Campaign in Aden

ISIS has moved through three operational phases in Aden as ground conditions changed in the city over the past year. The first phase was from March 2015 until August 2015 when Aden was contested between al Houthi-Saleh forces and Aden’s popular militias. ISIS militants conducted a spree of brutal attacks, such as the beheadings of al Houthi militants in March-April 2015. The second phase began after the Saudi-led coalition had recaptured most of Aden in early August 2015 and continued through September 2015. ISIS militants began destroying Christian sites in Aden and executed an “apostate agent” at the end of August. The third and ongoing phase began at the end of September 2015 as the Yemeni government began to re-establish itself in Aden as the de facto capital of Yemen and the coalition had shifted to stabilization operations. ISIS re-branded to operate under the name, “Wilayat Aden-Abyan,” at this point.[10] The re-branding also marked a shift in ISIS’s demonstrated capabilities.

ISIS Wilayat Aden-Abyan conducted its first spectacular coordinated attack targeting the temporary government headquarters and a coalition base in Aden on October 6, 2015.[11] The group launched four vehicle-borne improvised explosive devices (VBIEDs) in a single day, which remains the highest number of VBIED attacks from ISIS in Yemen in a 24-hour period. It has launched at least one suicide or VBIED attack every month in Aden since then.[12] It assassinated the governor of Aden in December 2015 and has made at least three attempts on his successor. ISIS Wilayat Aden-Abyan has also targeted Aden’s police chief.[13]

The explosive attacks constitute a campaign to disrupt the coalition’s efforts to secure the city. ISIS Wilayat Aden-Abyan attacks target high-ranking Yemeni government officials, coalition-backed security forces, and security recruits. The targeting of security recruits—young, unarmed, local men—distinguishes ISIS from AQAP, which has disavowed such attacks.[14] The October 6 attacks prompted the coalition to adjust its defense posture in the city to shift more expendable resources to points of contact. Sudanese troops deployed to Aden to join the Saudi-led coalition in mid-October and assumed responsibility for conducting patrols and manning checkpoints, relieving Emirati troops of these tasks.[15] The shift in posture lowered the risk of asymmetric attacks to the Emirati contingent, which had taken significant casualties in Yemen, and permitted the coalition to shift the more capable Emirati troops to more complex stabilization and counterterrorism missions.[16] It also likely contributed to the delay in the Yemeni government’s homecoming until early June 2016, a return which has not yet occurred.[17]

ISIS Wilayat Aden-Abyan is improving its tactics and becoming more effective as it sustains a regular tempo of attacks in Aden. ISIS began combining an explosive attack with suicide attackers using small arms fire to increase its effectiveness. A March 25, 2016, attack on a major coalition base in al Burayqah in western Aden was the first time ISIS Wilayat Aden-Abyan used this tactic. The attack, timed to coincide with the anniversary of the coalition’s air campaign “Operation Decisive Storm,” consisted of three suicide VBIEDs and what ISIS called an inghimasi ground assault.[18] ISIS will likely continue to use this type of attack against hardened targets such as military bases and training camps. An ISIS attack against a soft target – Yemeni military recruits in Aden – killed over 45 people on May 23, 2016. ISIS Wilayat Aden-Abyan launched a VBIED at young men queued at a recruiting center and a suicide bomber detonated an explosive-laden vest (SVEST) among recruits gathered outside the home of an army commander.[19]

Yemeni and coalition efforts to clear ISIS from Aden and the environs as well as the December 2015 schism within ISIS in Yemen may only have a limited and short-term effect on ISIS’s capabilities in Aden. The frequency of ISIS attacks in Aden was lower in November-December 2015, but resurged in early 2016. The schism may have temporarily caused ISIS to reset, but is unlikely to continue to affect the group. There has been a noticeable depression in the tempo of ISIS attacks in April-May 2016, which likely is a result of the coalition-backed clearing operations in Aden in February-March 2016.[20] The clearing operations sought to remove AQAP from pockets in Aden, but they also probably affected ISIS’s cells in the city.[21] It is not clear whether either group will be able to reconstitute inside of the city. The effectiveness in ISIS attacks in Aden has improved even as the tempo slowed, meaning that ISIS is carrying out fewer, but deadlier attacks.

ISIS replicates the campaign in al Mukalla

There are indicators that ISIS is replicating its explosive attacks campaign used in Aden in al Mukalla. The Hadramawt ISIS cell is likely a former AQAP cell that defected from the group, carrying over small arms training and possibly some explosives training. ISIS Wilayat Hadramawt was only active in Wadi Hadramawt until the April 23-24 coalition offensive retook al Mukalla from AQAP, and there are no indicators that ISIS had a presence in al Mukalla while it was under AQAP’s administration.

ISIS Wilayat Hadramawt conducted its first attack targeting Yemeni security forces at a base in al Mukalla on May 12, 2016. The group detonated a VBIED at the base’s gate and then detonated a second VBIED inside the compound.[22] ISIS may have also launched a third VBIED targeting the commander of the regional military district, which occurred shortly after the attacks against the base, though it is possible that AQAP conducted that attack. Neither group has claimed responsibility. Yemeni security forces found and cleared two additional VBIEDs on May 13, which were likely prepared for a second round of attacks in al Mukalla.[23] ISIS Wilayat Hadramawt is also targeting recruits in the city: an ISIS militant conducted an SVEST attack against a local recruitment center on May 15.[24]

Local Yemeni security forces, with coalition support, are working to clear al Mukalla and surrounding areas of ISIS and AQAP militants. There is a steady stream of reports from the city that security forces disrupted cells that are preparing for attacks.[25] The affiliation of these cells is not clear. It is not yet clear whether the joint efforts have fully cleared ISIS and AQAP cells to date, though operations are ongoing. The groups still retain a presence in Wadi Hadramawt and elsewhere, which could serve as a staging ground for attacks along the coast.

Likely Ramadan Surge in Yemen

ISIS increased its attacks in Yemen in Ramadan 2015 and will most likely surge again in 2016 to show strength and display a new capability.[26] ISIS uses the Ramadan season as a period of change. ISIS has included Yemen in its global Ramadan campaign in the past and will likely do so again. ISIS’s Ramadan campaign in 2015 aimed to demonstrate the group’s global strength, exemplified by same-day attacks on France, Tunisia, and Kuwait.[27] The group pursued its Ramadan objective in the Yemen theater by detonating four VBIEDs simultaneously in Sana’a on June 15, 2015, its first demonstration of VBIED capabilities in Yemen.[28] ISIS may seek to advance its Ramadan 2016 objectives in Yemen by conducting an explosive campaign in southern Yemen that will both undermine the Saudi-led coalition’s efforts to secure a friendly Yemeni government and draw support away from AQAP.

ISIS has not yet attempted to capture ground in Yemen as it has in Libya and elsewhere outside of Iraq and Syria, and is unlikely to do so in the coming year. The group probably does not have sufficient force size to seize and retain terrain, and it lacks the local relationships and military capabilities enjoyed by AQAP. It is therefore more likely to use explosive attacks to disrupt coalition-backed military and security operations.

ISIS Wilayat Aden-Abyan and Hadramawt may conduct spectacular attacks during Ramadan 2016 in Aden or al Mukalla, respectively. It is possible that the groups will coordinate simultaneous attacks, which would demonstrate that ISIS in Yemen has a fully centralized command node in Yemen and would be an indicator that the group is developing command capabilities like those demonstrated by ISIS elsewhere.[29] Simultaneous attacks would also indicate that ISIS has two distinct VBIED cells. ISIS Wilayat Aden-Abyan has not conducted a VBIED attack since ISIS Wilayat Hadramawt launched its attacks in al Mukalla. ISIS is less likely to target mosques in Aden and al Mukalla because the cities are nearly entirely Sunni, unlike Sana’a, where it has targeted mosques it labels as being affiliated with Zaydi Shi’a al Houthis. ISIS Wilayat Aden-Abyan and Hadramawt will probably continue to target hardened coalition or government sites as well as recruiting centers, which are more vulnerable to attacks.

A sophisticated ISIS attack or series of high-casualty attacks during the month of Ramadan would undermine the coalition-backed Yemeni government’s authority in Aden and al Mukalla. Insecurity in Aden remains a challenge to the government’s legitimacy and sustaining security in al Mukalla has been a priority, evidenced by the deployment of Emirati troops to secure the city.[30] Sustained coalition-backed efforts to clear Aden and al Mukalla of Salafi-jihadi cells may limit ISIS’s ability to conduct a major attack, however.

ISIS’s campaigns may also help it capture a larger share of the Yemeni Salafi-jihadi base from AQAP. ISIS Wilayat Hadramawt’s campaign in al Mukalla demonstrates the group’s capabilities and its desire to fight the Yemeni government today. AQAP had withdrawn from the city, calculating that it would be better to preserve its military forces and relations with the people than to bring violence to al Mukalla. ISIS may seek to exploit AQAP’s retreat by showing its will to fight the Yemeni state where AQAP no longer operates. ISIS’s continued attacks against soft targets such as police recruits may work against it, however. AQAP restrains its actions against what many Yemenis would consider to be civilians due to popular backlash, and ISIS’s attacks regularly cross the threshold in both al Mukalla and Aden.

ISIS will retain its foothold in Yemen and will probably be able to disrupt the coalition’s stabilization operations temporarily. Spectacular attacks against the al Houthis, Yemeni government, or coalition forces will amplify ISIS’s position on the global stage and may attract some Yemeni recruits drawn by the promise of immediate effect. ISIS is unlikely to see a significant change in its popular support in Yemen, and AQAP will remain the predominant Salafi-jihadi group because of AQAP’s relations with local populations. ISIS continues to develop its capabilities in Yemen, and as it becomes more advanced, the likelihood of ISIS acting as a spoiler to stability increases. Sustained pressure from Yemeni security and coalition forces will be required to prevent ISIS from prosecuting its campaigns in Aden and al Mukalla.

Emily Estelle contributed to the production of this piece.