The war in Yemen has grown increasingly intractable over the past several months as the long-simmering rift within the anti-Houthi coalition has widened, with violence between the pro-secession Southern Transitional Council (STC) and Hadi and Islah-aligned forces erupting in Aden, Shabwa, and Abyan.
The conflict between these parties is not new and centers around historical regional grievances and fractious politics, even within each side of the dispute. Although the underlying grievances fueling the conflict are old, Saudi Arabia and the UAE’s involvement in the war and support for divergent groups and political outcomes has created new dimensions and stoked animosity between the warring parties. As the situation escalates, the prospect of restoring Hadi to power and maintaining a united Yemen will only become more untenable. While the outcome cannot be predicted with any certainty, a look at the key players and underlying grievances does shed light on key turning points and likely future developments and stumbling blocks.
An Untenable Alliance
From the start, the anti-Houthi coalition was an amalgamation of Hadi-aligned military units, tribal militias, Islah-aligned groups, and various Southern secessionist groups that would have never allied themselves under normal circumstances. The strength and prominence of some of these groups, as well as the turmoil amongst them, has been deeply affected by Saudi and Emirati backing and political maneuvering.
The so-called “Southern question” regarding how the region should be governed has been lingering for decades, with intermittent surges in calls for secession tamped down, often violently, by the government. Many of the key players involved on both sides over the decades are still at the center of the simmering conflict in Southern Yemen, but others have gained prominence as a result of the current war and support from either Saudi Arabia or the UAE. In fact, the political and military moves Riyadh and Abu Dhabi have made since the war started have compounded longstanding grievances and undermined their own stated goal of restoring Hadi’s government and a united Yemen.
As the Houthis pushed south, already established and ad-hoc militias—including Aidroos al-Zubaidi’s Southern Resistance—became the first line of defense. Zubaidi’s group in al-Dhale was among the first to regain territory largely unsupported by external patrons, earning him new notoriety among secessionist circles. There was still an obvious need for the Saudi coalition to build local capacities as the Houthis seized increasingly more territory in Southern Yemen. Southern secessionist militias at the time were not well-organized or cohesive across the south, tribal militias were ill-equipped, and the Army was divided across countless lines, with loyalty being split between the late former President Ali Abdullah Saleh, Islah-affiliated General Ali Mohsen al-Ahmar, or President Hadi.
The UAE supported Zubaidi and other secessionist-leaning militias across the Southern governorates, ultimately equipping and training (some were trained outside Yemen) thousands of Southerners who now comprise the Southern Transitional Council and the closely linked military and police forces, including the Security Belt and Elite Forces, which span Aden, Lahj, al-Dhale, Abyan, Shabwa, and Hadramawt (Terrorism Monitor, June 14, 2018).
Meanwhile, Saudi Arabia continued to support Hadi, anti-Houthi tribes, and the Yemeni military units still loyal to Hadi. However, Hadi and Riyadh quickly realized that they were ill-equipped to take on the Houthis without further military, political, and tribal support, which is where the mercurial general, Ali Mohsen al-Ahmar, enters the fray. Ali Mohsen was the former commander of the northwestern military district and 1st Armored Division, having helped crush southern forces during the North-South civil war and led the Saada wars against the Houthis. Ali Mohsen is from Saleh’s Sanhan clan and is closely aligned with Islah. Mohsen also has a storied history of helping spread Salafist/Wahabi teachings and recruiting mujahideen to fight in Afghanistan, including Tariq al-Fadhli (Ali Mohsen’s brother-in-law), who helped found the Islamic Jihad Movement and allegedly helped assassinate southern leaders (Aljazeera, May 5, 2013; Terrorism Monitor, November 20, 2009; Terrorism Monitor, October 14, 2016). Ali Mohsen’s partnership with Hadi came with a price—the position of deputy supreme commander of the military and then vice president—but he delivered highly essential military units and brought with him a host of Islah-aligned militias and supporters (alaraby, February 23, 2016).
The problem with Ali Mohsen once again being in a position of power is multifaceted. The memory of the civil war is a significant motivation for secessionist sentiment and Ali Mohsen is viewed as the face of the North’s destruction of the South during the civil war. Mohsen has long been accused of ties to al-Qaeda in the Arabian Peninsula and was previously accused of facilitating the assassination of secessionist leaders. Ali Mohsen is also a prominent Islah-affiliated figure, which has long been at odds with Southern secessionist groups as well as the Emiratis. In fact, Emirati support for Southern forces and condemnation of other regional Muslim Brotherhood-affiliated groups, including actions against Qatar, served to inflame already existing animosity between the STC and Islah. UAE’s staunch opposition to Muslim Brotherhood-linked groups meant Islah was excluded from Emirati patronage and access to the training, equipment, and financing received by other southern groups, with Islah militias ultimately taking a backseat to the prominent security roles played by the Security Belt and Elite Forces. This only furthered disdain toward the STC.
Many Southern Yemenis—regardless of their affinity for the Southern Transitional Council—are quick to point out the economic and political marginalization their communities experienced as a result of what is often called the “failed unity” between the former Yemen Arab Republic in the North and the People’s Democratic Republic of Yemen in the South. Memories of pre and post-civil war Southern Yemen and the plundering of government institutions and southern resources loom large for those who witnessed it firsthand, including those who established Hirak, a peaceful southern protest movement that, in many ways, is a precursor to the Southern Transitional Council. Similarly, animosity against the parties involved, including President Hadi (a native southerner who acted as Saleh’s Defense Minister during the North-South Civil War), Ali Mohsen, and the Islah party continues.  With Hadi in exile and his government appointees running southern governmental bodies, it was only a matter of time before the parallels between post-unification Yemen and the current political balance erupted into open violence with the STC seeking to replace Hadi’s government.
The Southern Transitional Council, despite describing itself as the preeminent political body supported by all Southerners, has still faced significant challenges in garnering the support needed to completely govern and control areas outside its bastion of Aden. Many of these challenges stem from ideological, generational and regional differences, down to the tribal level and linked closely with previous divisions dating back to PDRY infighting but intensified by divergent Saudi and Emirati strategies.
The aging and largely exiled generation of prominent Southern figures that ran the former PDRY, founded Hirak, and witnessed unification and civil war has a significantly different outlook and approach in comparison to the younger and more militant generation of leaders and activists that led the charge during the Yemeni uprising and only gained prominence after the onset of the current war. Similarly, there are noticeable regional differences and divisions among southern governorates, particularly regarding the desire for outright secession. Also, Southern tribes and figures who had the virtue of enjoying northern patronage, much in the way that Hadi did, do not want to see those ties severed by secession.
The Southern Transitional Council, led by Aidaroos al-Zubaidi and Hani bin Brik, and its associated Security Belt forces have maintained de facto control over Aden and strong but not unchallenged support in its power axis of al-Dhale and Lajh, from which many prominent STC figures hail, including Zubaidi. Outside of these governorates, the STC also maintains significant support, with local councils and its Elite Forces sharing security duties with various pro-Hadi forces in Shabwa, Abyan, and Hadramawt. Despite notable support in these areas, the STC still faces major pockets of opposition—particularly in Shabwa—from a range of actors, including Hadi and Islah loyalists, as well as former PDRY and Hirak figures that are pro-Hadi and against the STC, divided along similar regional lines of the 1986 civil war between warring sides of the PDRY and those who joined Northern forces after unification.
Despite the turmoil, the STC and Hadi-aligned forces had managed to pull back and maintain a semblance of stability even after numerous armed clashes in Aden over the past several years. However, what has remained clear is that Hadi and his government have steadily lost legitimacy and the UAE’s moves to distance itself from the war in Yemen likely sped up the STC’s timeline for attempting to take control.
A Dangerous New Front
The STC and southern forces, likely embolden by the UAE distancing itself from the war, seized control of Aden in mid-August. The move came just days after a Houthi attack in Aden killed Munir al-Yafei (a.k.a. Abu al-Yamama), a prominent PDRY military leader who was also active during the Arab Spring (Aden al-Ghad, August 2). The combination of the UAE’s withdrawal and his death served as a catalyst for the current clashes, as STC members accused Ali Mohsen and Islah of infiltrating the government and working with the Houthis to target their forces.
After seizing control of Aden’s military bases and government facilities, on August 20, STC-aligned forces moved to take control of key strategic locations in other governorates. STC forces pushed into Abyan, Hadi’s home governorate, besieging Zinjibar and Lawdar before moving on to Ataq, the capital of Shabwa governorate (Aljazeera, August 20; Asharq al-Awsat, August 24). Pro-Hadi forces managed to regain some territory, primarily in Shabwa, and pursued STC forces near Balhaf, the site of key coastal oil infrastructure, pushing them back toward Aden.
While both Saudi Arabia and the UAE have publicly called for an end to the fighting, each side provided material support to their proxies, with Saudi Arabia conducting an airstrike on STC forces in Aden and the Emiratis striking Hadi’s forces near Zinjibar (alaraby, August 29; Middle East Eye, August 11). The Hadi government has lambasted the STC for conducting a coup and the UAE for its aggression and attempts to divide the country. Meanwhile, STC officials and activists have been quick to point out that the Hadi government has redeployed forces in order to prevent the STC from “controlling its rightful territory” instead of using the forces to fight the Houthis.  Similarly, as the coalition has called for an end to the fighting, Ali Mohsen’s forces have still been seen moving military personnel and equipment in preparation to retake STC-controlled areas (Twitter.com/yaseralyafai).
The UAE and Saudi Arabia, despite public statements to the contrary, are very much at odds with one another and now Riyadh finds itself in a considerably weakened position. The new front between the STC and Hadi-aligned forces will likely be a boon for both the Houthis and AQAP as resources and attention are focused on preventing major, prolonged fighting from breaking out in the South. Meanwhile, the turmoil could see new alliances of convenience that strengthen the Houthis position in a manner akin to the unusual alliance that had existed between the Houthis and Ali Abdullah Saleh, only this time the Houthis could potentially find willing partners in Ali Mohsen and Islah, or the STC.
Hadi’s Loss of Legitimacy and Potential Future Developments
The coming months are likely to see significant political and military maneuvering as the STC and various groups from the pro-Hadi camp attempt to strengthen their position. Both the STC and Islah have allegedly opened up lines of communication with the Houthis and could seek to strike an alliance if an acceptable ceasefire is not made. If either side does align with the Houthis, Saudi Arabia, and Hadi will find themselves in a decidedly unwinnable situation.
Regardless, Hadi’s government no longer holds any legitimacy, particularly in the eyes of much of Southern Yemen and certainly not with the Houthis. In previous conflicts, outside powers have looked to the second in command as a potential successor or compromise for warring parties, but Ali Mohsen is among the most polarizing political/military figures in the country and his control of the government is entirely untenable if the country ever hopes to achieve peace. Mohsen’s connection to Islah will also preclude him from being considered as viable by the UAE. Similarly, there are no figures that currently hold political appointments with enough clout, and that have remained relatively neutral or untainted by the unsavory alliances the war has brought about.
As the UAE and Saudi Arabia seek to broker peace between the STC and Hadi, they will need to delicately balance their short-term gestures of goodwill toward each side of the conflict as a perceived imbalance will undoubtedly see resumed fighting. Similarly, they need to balance their divergent strategic interests. The coalition must also be considering longer-term plans as to how to answer the Southern question and find a more palatable leader to potentially succeed Hadi. There are few politicians who have made it out of the conflict relatively untainted. One figure does, however, stand out and that is Khaled Bahah, who served as Hadi’s Vice President between 2015 and 2016 before being sacked and replaced by Ali Mohsen. Bahah is known to be tolerated by the Houthis and the STC and is among the few former highly-ranking political figures to have returned to Aden, and it would not be surprising to hear his name surface more frequently in the coming months (Aljazeera, October 19, 2014).
Yemen is unlikely to ever be put back together again and the question for the future is whether the country will be split along previous North-South lines or carved into a federal system. Secession is unlikely to garner the international support it would need, particularly as it could leave the Houthis with power along Saudi Arabia’s border and the Kingdom has repeatedly expressed their opposition to such an outcome. A federal system is more likely but comes with the issue of who would subsidize less affluent governorates and would still require identifying a consensus political figure, among other serious challenges.
 Based on author’s interviews with dozens of Southerners in Aden, Abyan, Hadramawt, and Shabwa between 2016-2019
 Authors interview with Aden based activist on August 30, 2019.