Yemen’s history has seen a number of alliances of convenience unravel spectacularly, most recently the three-year marriage of convenience between former President Ali Abdullah Saleh and the Zaydi Shia Houthi rebels, who on December 4 killed Saleh in the capital of Sanaa after several days of fighting between their militias and his loyalists.

Saudi Arabia and its allies have painted Saleh’s death as proof that the Houthis cannot be trusted and have argued that the former president empowered an extremist militia, allowing Iran to gain a powerful foothold in the strategically important, impoverished country.

Yet in Riyadh’s attempts to unite the multiple forces operating on the ground across Yemen, it has also come to sponsor a deeply controversial figure: Major General Ali Mohsen al-Ahmar, a onetime Saleh ally who split from his regime in 2011.

Mohsen is an influential player in the network of tribal and Sunni Islamist groups whose center of gravity is Islah, widely (and inaccurately) known as “Yemen’s Muslim Brotherhood.” He also stands accused of helping to cultivate the groups that ultimately became Al-Qaeda in the Arabian Peninsula, the local franchise of the global extremist movement.

Mohsen has been able to position himself as Saudi Arabia’s best hope of winning a military victory against the Houthis and as the last line of defense for Yemen’s republic (he and a growing number of Yemenis charge that the Houthis want to restore the imamate, a strictly hierarchical religious monarchy that – over the 1,000 years it prevailed in Yemen – marginalized tribesmen of low birth).

If he is able to achieve results on the ground, Mohsen may well be able to build on his current position and engineer an unlikely return to power. If and when this were to happen, his past is likely to come under much greater scrutiny. Any future role for Mohsen is likely to be the source of anger for Southern groups who still blame him for the excesses of Yemen’s 1994 North-South civil war.

A Comeback

Early on in Yemen’s civil war, reports emerged that Mohsen al-Ahmar was making a comeback. Mohsen, a controversial and once shadowy figure, had fled Sanaa in September 2014 as Houthi militias seized the city. Once described as the “iron fist” of Yemen’s Sanaa-based regime, he was quickly written off as a spent force.

Saudi Arabia entered Yemen’s civil war in March 2015 and it soon became clear that Mohsen was training and deploying soldiers from a base in Saudi territory to fight alongside tribesmen battling the Houthis across multiple fronts. Mohsen has since undergone a remarkable change in fortunes. The latest shift came in early December, when his feud with his clansman Ali Abdullah Saleh – which arguably lies at the heart of Yemen’s war – came to an abrupt end, just as it seemed they were about to reconcile.

A decades-old partnership turned rivalry ended with Saleh shot dead at his home in Sanaa, killed by the Houthis, who he partnered with to exact his revenge on former rivals including Mohsen. His Sanhan clansman, meanwhile, was at the head of an army about 60 miles away, apparently ready to reclaim the capital.

Saleh’s death leaves Mohsen as the last surviving member of a group of tribesmen who rose to power in the late 1970s and clung on for the next three and a half decades. He is crucial to Saudi Arabia’s plans to win the Yemen war militarily, and may be the last hope for the survival of Islah, Yemen’s main Sunni Islamist party, which is caught between the Houthis and a regional environment that is increasingly hostile to Islamists. Yet his questionable past presents a considerable liability to Saudi Arabia and the United States if he maintains his current position or achieves higher office. Even his greatest supporters, meanwhile, question whether he is willing or able to act.

Roots of the Republic

The roots of Yemen’s current chaos lie in the 1962-70 civil war. During the war, Arab nationalist republicans, led by military officers and tribesmen, lined up against supporters of the imamate, a religious monarchy led by so-called Sayyids (Zaydi Shia Hashemites, descendants of the Prophet Muhammad) who imposed a tight set of restrictions, including religious education, age, and purity of bloodline, on anyone hoping to achieve high office.

Symbolic of the republicans’ success in toppling the imamate was the rise of a small group of young military officers from the hitherto marginal Sanhan clan to the commanding heights of power in Sanaa. Best known among them was Saleh, the former tank commander who maneuvered his way first to the head of the military and then to the presidency at the age of 36.

Urban legend in Yemen has it that Saleh’s ascent was planned during qat chews attended by Sanhan clansmen who had fought for the republican cause during the war. The Sanhan agreed, the story goes, that the gregarious and wily Saleh, at the time heading the military command in Taiz governorate and backed by the region’s business leaders, would act as frontman for the clan. A line of succession was plotted out – an important measure given the short life expectancy of Yemeni presidents at the time. If and when Saleh was killed, he would be replaced by Mohsen, who was building a power base at the military’s central command in Sanaa.

President Ahmad al-Ghashmi was assassinated in June 1978, less than a year after his predecessor Ibrahim al-Hamdi had also been killed (Hamdi was the republic’s third president in a decade). The Sanhan took the initiative, seizing key military installations, lobbying for tribal support, and raising funds to buy the loyalty of the military rank and file. Mohsen, a close Saleh ally and his senior in the Sanhan hierarchy, took over the military headquarters in Sanaa. A month later, Saleh was president.

Bolstered by a second pact between the Sanhan and an influential tribal sheikh, Abdullah Hussein al-Ahmar, the putative republic was prevented from unraveling into an accelerating cycle of assassinations and political intrigue, as it had seemed poised to do. Saleh would remain in power for the next 33 years. In the interim, he would put down a leftist insurgency, unify his republican North Yemen with the socialist South in 1990, and win a civil war against the Southerners after an attempted breakaway in 1994, before becoming mired in diverse challenges to his authority, including from his closest allies.

Murky Past

Mohsen was a constant, if shadowy, presence throughout the Saleh regime. His First Armored Division came to be seen as the country’s strongest military force. Mohsen was instrumental in the creation of the Political Security Organization, the Yemeni mukhabarat, which had close ties to the Saudi and Pakistani intelligence services. He also played an important role in recruiting Yemenis to fight in Afghanistan as mujahedeen – he allegedly visited Osama bin Laden-run training camps in the 1980s – and in reassimilating them upon their return.

Many Yemenis from the historically Zaydi highlands had shifted toward Sunni interpretations of Islam after the revolution of the 1960s, part of a broader rejection of the doctrine used to justify social hierarchy during the rule of the Zaydi imams. Mohsen, who it is said came under the influence of Muslim Brotherhood ideology during time spent in Egypt, was seen as a true believer, the regime’s religious conscience, contrasting with Saleh, a rumored bootlegger, whiskey enthusiast, and arch pragmatist. Mohsen was close with leading members of the Yemeni wing of the Muslim Brotherhood like Abdul Majid al-Zindani, a onetime mentor of bin Laden, and leaders of Islah, the Sunni Islamist party to which Zindani belonged (despite his long association with Islah, Mohsen has remained a member of the General People’s Congress, the party he and Saleh founded in the 1980s).

In 1990, Saleh engineered a unity pact with the hitherto independent socialist South Yemen. In the years that followed, a number of prominent socialist leaders were killed, apparently by Mohsen and Saleh’s jihadist allies. During the 1994 North-South civil war, Mohsen used returning jihadists to help crush Southern military forces in a convincing military victory. Soon after, he came under scrutiny from foreign intelligence agencies for his ties to groups like the Aden-Abyan Islamic Army and the Islamic Jihad Movement, predecessors to AQAP. Both Mohsen and Saleh were accused of using AQAP to serve their own interests. Mohsen also garnered a reputation for graft, with his inner circle playing a major role in fuel smuggling and, allegedly, extorting foreign oil companies hoping to work in Yemen.

Thanks to rising oil output, Saleh and those around him got rich. But, by the late 1990s, cracks were beginning to show. Saleh, emboldened by growing majorities won during parliamentary and presidential elections, began to hand control of new intelligence, security, and military bodies to his sons and nephews. Many of the new organizations were set up as rivals to similar institutions controlled by other members of the Sanhan elite, like the Political Security Organization. Clan members worried that Saleh was grooming his son Ahmed Ali Saleh for the presidency while gradually eroding the power of his potential rivals. The sons of Abdullah al-Ahmar, who saw themselves as future leaders, were also suspicious. Shortly after one Sanhan clan member, Abdullah al-Qadhi, complained, he died in a mysterious helicopter crash, further denting the increasingly fragile covenant that had held the country together since the late 1970s.

Regime Strain and Revolution

In the early 2000s, Saleh sent Mohsen north to lead the fight against the Houthis, at the time a small insurgent group whose founder, leader, and namesake, Hussein Badr al-Din al-Houthi, was killed in an initial round of fighting with the government in 2004. Mohsen struggled to contain the Houthis during six rounds of fighting from 2004-10. Members of the Sanaa elite speculated that Saleh – known for cynical alliances and divide-and-rule tactics – was quietly lending support to the insurgency to keep Mohsen occupied and erode the strength of the First Armored Division, while he used U.S. funding to grow Ahmed Ali Saleh’s rival Republican Guard. It would later emerge, through Wikileaks, that during the sixth round of hostilities, military commanders loyal to Saleh had tried to convince Saudi Arabia, whose air force was taking part in the conflict, to launch a strike on Mohsen’s military headquarters in the Houthi heartland of Saada. Mohsen, meanwhile, was accused of supporting Salafist fighters who were also battling the Houthis in the towns of Dammaj and Kitaf.

Then, in 2011, protesters took to the street at first to call for reform and later to demand that Saleh step down. After soldiers opened fire on protesters on March 18, 2011, Mohsen announced that he was joining the uprising, as did Islah and the al-Ahmar family. Heavy fighting soon broke out on the streets of Sanaa and Taiz, with Mohsen, Islah, and the al-Ahmars on one side and Saleh loyalist military and tribal forces on the other. In June 2011, a bomb went off at Saleh’s private mosque in Sanaa, nearly killing the president. Saleh insiders have claimed that Mohsen and Islah were behind the bombing. In November 2011, weakened by the bombing and threatened with debilitating sanctions and a travel ban by Western governments, Saleh gave in to international pressure and agreed to hand over power to his vice president, Abd Rabbu Mansour Hadi. The Sanhan pact was dead.

Initially, Mohsen and Islah looked to be among the biggest winners from the 2011 uprising, especially as Hadi moved to sideline Saleh loyalists from the government, military, and security services, replacing them with his own allies and Islah insiders. In 2012, Hadi removed Ahmed Ali, Saleh’s son, from the command of the elite Republican Guard and made him ambassador to the United Arab Emirates. Mohsen was also removed from command of the First Armored Division, and made a military advisor to the president, a position from which he was able to effectively continue to maintain control over the units loyal to him.

During the transitional period that followed Saleh’s ouster, from 2012-14, the rivalry between Saleh and his General People’s Congress party on the one hand, and Mohsen and Islah on the other, remained a constant. The Houthis, who had exploited the power vacuum in 2011 and seized undisputed control of the northern Saada governorate, also began to battle their way south toward Sanaa – with Saleh’s tacit support.

By July 2014, the Houthis had overrun most of Amran governorate, the al-Ahmar stronghold, and had arrived in Amran city, about 30 miles north of Sanaa, killing Ahmed al-Qushaibi, an important military commander and Mohsen’s ally. By September 2014, the Houthis were on the outskirts of Sanaa, overlooking the First Armored Division camp that had been a symbol of Mohsen’s strength for decades. Mohsen allies saw Saleh’s hand behind the Houthis’ rise. The former president, they contended, had done the unthinkable and taken the Sayyids’ side in the hope of crushing his former allies and returning to power.

Another Double Cross?

It was during the ensuing siege of Sanaa, people close to Mohsen claim, that yet another double cross took place. Before and during the fighting around Sanaa, Mohsen and senior Islah officials had pressured Hadi to declare war on the Houthis and issue orders for the military to defend the city with help from militias put together by the al-Ahmars and Islah. At the time, the only forces fighting the Houthis were Islah-affiliated tribal militias and Mohsen loyalists. Mohsen believed that he could rally several thousand fighters from the military, security services, tribal affiliates, and Islah to fight the Houthis, people close to him say, but was unwilling to send them into battle without Hadi’s explicit endorsement.

Mohsen and Islah officials feared that they were being played. In private, Hadi was telling them to fight the Houthis but they worried he was presenting the fighting to foreign diplomats as a sectarian struggle between two nonstate groups, and that he planned on using the fighting to discredit both the Houthis and Islah.

During a September 21 meeting at the presidential palace, according to the same people, Mohsen gave Hadi an ultimatum: “Announce that the state is at war with the Houthis and mobilize your Presidential Guard, and I will mount a defense of the city. Don’t, and I will walk away.” Hadi equivocated. “Fight the Houthis and I will make an announcement soon,” he reportedly responded. Mohsen, smelling a trap, walked out, ordering his men to stand down. Within hours, the city was under the Houthis’ – and Saleh’s – control.

Return to Power

At first, it seemed that Mohsen’s dubious past would limit his ability to win a formal position in the war against the Houthis. When he first reappeared on the scene in mid-2015, diplomats and Saudi officials were clear in saying that he would not be afforded a senior role due to his murky dealings with Islamists and unpopularity among large segments of Yemeni society, in particular, southerners and, of course, the Houthis themselves. But as the conflict has dragged on, his stature has grown. He has recruited tribesmen and former soldiers into the ranks of the new, ad hoc Yemen National Army. While much is made of the army, there are no figures on how many men Mohsen has under arms, or what the formal command structure is. Despite limited battlefield successes it has come to be seen as a military force to be reckoned with. In many ways, Mohsen has achieved what Saleh had likely hoped to: As the Houthis have risen, he has made himself the most attractive, or at least the least bad, option for foreign powers.

In 2016, Hadi named Mohsen vice president and deputy commander of the armed forces. At the time, the move infuriated U.S. officials, who believe that Mohsen still has ties to extremists, and the UAE government, whose de facto ruler Mohammed bin Zayed al-Nahyan sees the Muslim Brotherhood as a threat on par with al-Qaeda and Iran.

Yet both countries’ positions have thawed. Matthew Tueller, the Jeddah-based U.S. ambassador to Yemen, has met with Mohsen on a number of occasions. In early 2017, a new “troika” council was set up to coordinate among the UAE, which is the main player in south Yemen, Saudi Arabia, and the government of Yemen. Mohsen chairs the council, which includes Brigadier General Ahmed al-Asiri, Saudi Arabia’s deputy intelligence chief, and Ali bin Hamad al-Shamsi, the deputy secretary general of the UAE’s National Security Council. Days after Saleh’s death, Mohsen met with senior U.S. military officials. Most notably, in mid-December, Mohammed bin Zayed met with leading members of Islah in Riyadh, a major break from past policy to reject any overtures from the party.

Emperor’s New Clothes?

Yemeni observers question, however, whether Mohsen is willing – or able – to act decisively. When Saleh announced his split from the Houthis and called for an armed uprising against his erstwhile allies, it was widely assumed that he had done so as part of a deal with the coalition and, by extension, Mohsen. Yemeni media outlets aligned with Hadi and Mohsen announced that the major general had issued a command for his men to march on Sanaa in the colorfully named Operation Arab Sanaa. But the offensive was not forthcoming.

The main frontlines of the war around Sanaa did not move, possibly because neither Saleh nor Mohsen could convince the seven “collar tribes” that surround the capital – so-called because of their stranglehold on the city ­– to join their cause. In the days after Saleh’s death, it was UAE-backed southern forces that made progress on the ground, pressing up the west coast from Mokha into neighboring Hodeidah governorate.

The Houthis now exercise unprecedented control over Yemen’s northern highlands, but their popularity among most Yemenis – already minimal – has plummeted during a purge of Saleh loyalists and senior General People’s Congress figures, and a broader crackdown on opposition to their rule in the highlands and along the west coast. There could be an opportunity for Mohsen to do business with former Saleh allies, perhaps even his favored son, Ahmed Ali, and bear down on Sanaa, convincing the collar tribes that he is their best bet, restoring the Sanhan to power, this time without Saleh to contend with.

The longer he waits, the more time the Houthis have to consolidate their stranglehold over the north, however. If he allows UAE-backed forces to take the initiative, Mohsen may find that he and his allies in Islah end up being seen as less important than the Houthis and the southerners, both of whom view him and Islah as enemies. Many Islah insiders worry that Saudi support for Mohsen and the other Islah allies will only last as long as the war, after which the Emirati allergy to the Muslim Brotherhood will once again shape the position of Saudi Crown Prince Mohammed bin Salman.

Will Ali Mohsen al-Ahmar make his move? The story of Yemen over the past six years has been one of treachery, double crossing, and broken promises. It has also been one of uncomfortable unmaskings. In 2011, neither Saleh nor Mohsen was willing to commit entirely to outright war, as both reckoned their forces were too evenly matched to score an outright victory. In 2014, Mohsen and his allies including the al-Ahmars, still seen as an important military power, were soundly routed by the Houthis on multiple occasions before they arrived on the outskirts of Sanaa. And, in December, Saleh, who was still reckoned by many Yemenis to be the Houthis’ match, was dispatched in a little more than 48 hours. The Saudis, having predicted that the Yemen war would be over within a matter of weeks after their entry, find themselves in a quagmire.

Yet identity is fluid, nowhere more so than in Yemen, and many of those who currently support Mohsen do so more because of what he stands against – the Houthis – than what he stands for. For others, he represents the last line of defense of the republic. Regardless, the defeat of the Houthis is a top priority for the Saudis, Emiratis, and, as the involvement of Iran in the Yemen war becomes clearer, for the United States.

The longer the war lasts, the greater Saudi Arabia’s dependency on Saleh’s former right-hand man is likely to be. With the UAE apparently warming to the idea of Mohsen, his return to a position of power becomes more likely, bringing the last of the Sanhan elders full circle – if, that is, he can convert his restored prestige to battlefield successes.