Saudi Arabia and the United Arab Emirates’s deepening intervention in Yemen is the triumph of hope over experience. Riyadh’s latest campaign in Yemen began in 2015 to topple the then-triumphant Houthi rebels, whom Saudi leaders considered too close to Iran. Rather than dissuading their good buddies in Riyadh from this dangerous course, the UAE too has plunged into the morass, also hoping to set back Iran. Unlike in Egypt, where the two helped bring about a coup that put President Abdel Fattah el-Sisi in power, the result has been a disaster. This is true not only for Yemen, whose war and humanitarian crisis only seem to worsen by the day, but also for the UAE and Saudi Arabia themselves, with Iran in particular gaining influence at their expense.

A Pattern of Intervention

Saudi Arabia has intervened periodically in Yemen since the start of the modern Saudi state. For many centuries, the Zaydi Imamate of Yemen controlled part of what is now the Asir Province in Saudi Arabia, and the two countries fought a border war in 1934. The Zaydis are Shiite, and their leaders’ descendants would form the core of the Houthi opposition today. Border clashes continued as late as the mid-1990s, and an agreement defining the border would only be finalized in 2000.

Aside from territorial disputes, Saudi Arabia feared the wrong faction would come to power in Sanaa. In 1962, when Yemen plunged into civil war between Imamate and Arab nationalist factions from Yemen’s military, the Saudis (in addition to Iran and Jordan) intervened on behalf of the Imamate, while Egypt intervened to support the Arab nationalists, drawing on Soviet support. In a lesson the foreigners would fail to heed in the future, the intervention fueled the war but left the outside powers exhausted. In 1970, a negotiated agreement put the Arab nationalists in charge, but the Imamate faction received several prominent positions and a share of the patronage.

In 1990, South and North Yemen united under the leadership of the North’s longtime strongman, Ali Abdullah Saleh, who proved adept at dodging his many enemies and consolidating his power—“dancing on the heads of snakes,” as he called it. Yet Yemen remained weak. The South never fully integrated, the country was desperately poor, and resentment and anger at Saleh simmered.

During these years, Saudi Arabia meddled from time to time, trying to buy local leaders, stop terrorists linked to al-Qaeda in the Arabian Peninsula, weaken Marxist forces in the South, undermine the government in Sanaa when it went against Riyadh’s wishes, and otherwise spread its influence. Yemen’s politics and leaders seemed to get under the skin of the al Saud family. To change the country from the bottom-up, Riyadh encouraged the spread of Salafism in Yemen, funding mosques and preachers and otherwise trying to advance its austere and anti-Shiite interpretation of Islam. However, while Saudi Arabia at times won over a particular leader or killed or stopped a terrorist, most Yemenis remained fiercely nationalistic and suspicious of Riyadh. They were happy to take Saudi money, but they often stopped short of fulfilling Riyadh’s ambitions.

Instability intensified in the 2000s. Houthi rebels based primarily in the Saada region posed a particular problem. The Houthis resented their poor treatment by Sanaa and loss of state patronage. For many years, they fought to receive some of the state’s spoils rather than to break away or to replace Saleh. They became more radical, however, when they realized that the years of negotiations and the 2011 revolution during the Arab Spring would not restructure power in Yemen as they hoped. In addition, the bitter anti-Shiite message of the Salafi proselytizing angered the Houthis.

Enter the Houthis

The latest round of intervention began in 2015. The Arab Spring spilled over into Yemen in 2011, forcing Saleh to abdicate reluctantly in favor of his deputy, Abdrabbuh Mansour Hadi. Continued violence from al-Qaeda in the Arabian Peninsula, separatist sentiment, Saleh’s attempts to undermine Hadi and restore his and his family’s position, a collapsed economy, and other maladies kept the Hadi government weak despite international goodwill.

Houthi rebels took advantage of the chaos, conquering Sanaa and eventually much of Yemen in 2014 and 2015, and Hadi fled first to Aden in the South and then to Saudi Arabia. Saleh, always opportunistic, allied the military forces still loyal to him with the Houthis, despite having fought them fiercely when he was in power. At the time, the Houthis had limited but real links to Iran that alarmed Riyadh and Abu Dhabi, which saw Tehran as ascendant not only in Yemen but also in Iraq, Lebanon, and Syria. The Houthi core area also extends to Yemen’s border with Saudi Arabia, which the paranoid Riyadh often interprets as Iranian presence on its frontier.

Saudi Arabia and the UAE intervened to put Hadi back in power, and Saudi officials declared the intervention would be over within weeks. Bahrain, Egypt, Jordan, Kuwait, Morocco and Sudan all joined the fray, largely out of a sense of obligation to the UAE and Saudi Arabia rather than genuine concerns about Yemen. Djibouti, Eritrea and Somalia opened their airspace and facilities to the coalition. Qatar was also a token coalition member until strains between Doha and the UAE and Saudi Arabia led to its expulsion.

In addition to the Saudi and Emirati military role, the UAE also paid for Colombian mercenaries, while Saudi Arabia recruited thousands of Sudanese soldiers. The United Nations also claims that Eritrea deployed troops, and the UAE uses Asmara’s airport for some of its operations. The United States quietly supported the intervention with intelligence, aerial refueling, and munitions.

At first, the Saudi and Emirati campaign seemed to make progress, helping forces loyal to Hadi take Aden and then much of southern Yemen. Riyadh supported an array of tribal and military forces that worked with Islah, Yemen’s most important Sunni Islamist party and an offshoot of the Muslim Brotherhood. The UAE loathes the Brotherhood (and has undermined its power in Libya, Egypt, and elsewhere) and supports southern secessionists and Salafists, who distrust Islah and see the Houthis as apostates.

Progress slowed and then largely came to a halt, however, as Saudi and Emirati-backed forces tried to move on areas closer to the Houthi heartland. Saudi hopes of a quick victory, like most of their hopes for Yemen, proved an illusion. More than three years later, Riyadh has flown more than 100,000 sorties and spends billions a month on the war. Airstrikes managed to destroy much of Yemen’s already-tottering infrastructure and kill thousands of civilians, but the Houthis held on. (Look here to see who held what as of June 2018.) Meanwhile, the factions often turned on each other. Saleh turned his coat and agreed to work with the Saudis in 2017, but the Houthis killed him before this flip could pay off. At least some of the forces once under his command now work with the UAE, but the anti-Houthi forces are divided. In Aden, forces backed by the UAE fought fighters loyal to Hadi, whom Saudi Arabia backed, over bases and facilities. UAE leaders reportedly consider Hadi a serial incompetent, while the Saudis are more willing to work with Islah, which Islah tried to distance itself from the Muslim Brotherhood to please the UAE and Riyadh. For obvious reasons, Riyadh also focuses more on border security than does the UAE.

The intervention today: The UAE Takes the Lead

Although Saudi Arabia is the historic meddler in Yemen and many usually describe the intervening coalition as “Saudi-led,” today the UAE plays an important and often leading role. More than 1,000 Emirati forces are deployed throughout Yemen, mostly in the South, and it trained thousands of locals, including many southern separatists who are trying to seize the day and end the dominance of the north. Saudi Arabia takes the lead on the air campaign and provides considerable funding, but it does not match the UAE’s presence on the ground. In Yemen, the UAE forces draw on the counterinsurgency experience they gained fighting with NATO forces in Afghanistan. Not surprisingly, the UAE has taken casualties—more than 100.

Today, UAE-led forces are trying to make a dramatic push and end the stalemate by capturing the port of Hodeida, the Houthi's most important port through which food and other supplies go into Houthi-dominated areas. (The Saudis claim that Iranian weapons also flow through the port.) The UAE assembled as many as 25,000 fighters backed by air cover and with armored vehicles against a few thousand Houthis, most of whom are recent recruits. The UAE-backed forces include fighters who once fought the UAE’s allies because they were loyal to Saleh—now they follow his nephew, who believes the wind is blowing from Abu Dhabi and Riyadh. In addition, the UAE forces are better trained than in 2015. The urban battlefield, however, heavily favors the defenders, and Iran and Hizballah probably taught the Houthis how to exploit this terrain. Hodeida, moreover, is not the only port available to the Houthis, and smuggling is a proud Yemeni tradition. As such, the Houthis will likely have access to arms in any event. In addition, they have Iranian-supplied ballistic missiles that can harass Saudi Arabia.

What’s next?

An outright coalition military win is unlikely, though the UAE-backed forces have a tremendous advantage in weaponry, numbers, and money, making the capture of Hodeida seem likely. However, the Houthis will continue to hold territory in their heartland, where much of Yemen’s population lives. Additionally,even if they lose Sanaa and other major cities, they have proved that they can and will wage a relentless guerrilla campaign. To back their claim, they still have tens of thousands of men under arms. Even putting the Houthis aside, it is not clear what political solution would satisfy the disparate coalition the UAE and Saudi Arabia have put together.

Even ignoring the disaster in Yemen, the Saudi and Emirati intervention failed on its own terms. They are caught in the Yemeni quagmire. Hadi is not in power, their allies fight one another, Al Qaeda is stronger, and Yemen is less stable than before. Additionally, and most importantly from the Saudi and Emiratis’ perspective, Iran is stronger. Although the Houthis are hardly Iranian puppets, they work with Iran by necessity, and its influence has grown as a result. Now, Tehran has an ally that can threaten Saudi Arabia and shipping in the Red Sea.

The civil war exacerbated Yemen’s desperate poverty, pushing the country even closer (or, more accurately, farther over) the brink. Around 10,000 people have died in the war, roughly half of them civilians. Yet, that pales before the high but unknown death toll from the other horsemen that ride along with war: disease and famine. More than 50,000 children died of starvation and disease in 2017, and hundreds of thousands of Yemeni children suffer from acute malnutrition. Three million Yemenis are now displaced. According to the United Nations, 75 percent of Yemen’s 22 million people need assistance, and more than 11 million fall into the category of “acute need,” with imminent starvation staring them in the face. Further, the country suffered the world’s largest cholera outbreak last year. In parts of the country, the UAE provides some humanitarian aid, and Saudi Arabia also provides limited support—but not nearly enough to offset the disaster facing the entire country. Repeated UN attempts at negotiation have foundered, and today Yemen is home to the world’s worst humanitarian crisis.

Al-Qaeda in the Arabian Peninsula (AQAP) capitalized on the chaos. Somewhat belatedly, Saudi and Emirati airstrikes began to strike AQAP bases, and the intervening powers tried to create a coalition of Yemeni military and tribal forces. They succeeded in dislodging the group from Aden and several other important areas, including the port of Mukalla. However, AQAP persisted, working with tribes and capitalizing on locals’ anger at foreigners and central authority. Saudi Arabia, the UAE, and their allies lack the forces to occupy large parts of Yemen to ensure AQAP does not enjoy safe havens or return to cleared areas.

Saudi Arabia and the UAE both look incompetent and cruel, a deadly combination. An end to their interventions would leave both of them, and Yemen, better off.