The Rise of the Houthi Rebels: From Insurgents to Global Geopolitical Threat

In October 2023, the trade ships of the entire world came under attack. Off the coast of the Red Sea, along one of the most critical shipping lanes on Earth, missiles and drones crashed down onto container ships, oilers, bulk carriers, and more. All at once, the global economy was held hostage, in an attack that few people realized was coming, by a group few people had ever heard of, using weapons few people realized that they had.

Before long, the entire world knew their name: the Houthi rebels. Sitting on a massive patch of territory in the sovereign nation of Yemen, the Houthis had gone under the radar for decades across much of the world, and now, they intended to force a reckoning. Over the last year and more, that reckoning has played out painfully, and it is not likely to end anytime soon.

The history of the Houthi rebels requires an exploration of who they are, what they believe, what they want, and why they intend to become the entire world’s problem. Perhaps predictably, the answers to each of those questions start with just two words: It’s complicated.

The Ingredients of Rebellion and Yemeni Reunification

Creating a rebel movement is like creating a gourmet meal. You have got to have all the right ingredients on-hand, and you have got to add them together in the right order. You have got to have an agitating force, you have got to have heat, to transform the ingredients you started with into a boiling, searing reaction.

You have got to add spices, and the right spices at that, to transform your creation from something that will quickly become unappealing for the people consuming it, into something that can sustain over the entire course of a meal. Go too much or too little with a social movement, in any number of directions, and you might get a temporary uprising; you might get a new political party; you might get government repression; or you might even get complete disinterest from the people themselves. To create rebellion, the conditions have got to be just right, and in Yemen, there were three key conditions that were just right, at just the right time, to transform a movement into a revolution.

Those three conditions: national reunification, political upheaval in a religious group, and the failure of Yemen to truly cohere into a single nation. First, national reunification. Although Yemen might not rank very high on the list of nations that caught the world’s attention, during the Cold War years, for having been split in two, Yemen was nonetheless a member of that dubious exclusive club.

Starting in 1967, the southern and eastern portions of the nation of Yemen—including all of its southern coast, and most of its vast, open desert—were known as the People’s Democratic Republic of Yemen. They were a communist regime, still the only one to govern a nation in the Arab world across all of history, and among other things, they oversaw a mass exodus of people from southern and eastern Yemen to the other half of the country—known, back then, as the Yemeni Arab Republic. The entire affair was classic Cold War; the communists were backed by the Soviet Union, the republicans were backed by the Americans and the Saudis, and the two sides were deeply, and rather predictably hostile to one another until 1990, when they finally reunified into the Republic of Yemen.

But during the Cold War years, in the Yemeni Arab Republic, a religious sect known as the Zaydis endured decades of mistreatment by the republic’s ruling general, a man named Ali Abdullah Saleh. Saleh was Zaydi himself, but in a practical sense, that didn’t matter much. To give a bit of religious context, it’s not universally agreed whether or not the Zaydi faith can be properly included under Shia Islam, but those who do include it typically refer to Zaydism as one of the five major branches of Shia faith.

Qualitatively, however, it bears some resemblance to Sunni Islam as well, and has little in common with the Shia Islam practiced in Iran, home of the largest Shia population on Earth. About forty percent of Yemen’s population are Zaydi, living primarily in the northern parts of the country where the Yemeni Arab Republic held power, and until the republican revolution, the Zaydis had lived at the hierarchical apex of an imamate there, a long-lasting sovereign state that survived for over a millennium. When Yemen reintegrated, the republic’s leader, Saleh, became the leader of the new Yemeni nation—and with him, came his treatment of the Zaydi population.

The third critical factor that led to the Houthis is Yemen’s failure to come together as a truly cohesive state. During his time in power, Saleh had neither the backing nor the military strength to rule Yemen by force, and the Zaydis weren’t the only people under his control who chafed against the idea of unification. A southern movement called Al-Hirak splintered off into rebellion in 1994, and have advocated autonomy and secession ever since; the al-Qaeda organization would take root across part of the country, and the Ansar al-Sharia organization along with it.

The power and authority that Saleh did exert, he created and propagated by way of dealmaking and political maneuver, trying to manage Yemen’s factions, unify them, or play them against one another, like an unruly court of nobles in a medieval kingdom.

The Believing Youth and the Birth of Ansar Allah

One such faction was known as the Houthi tribe. Hailing from ancestral homelands in the country’s north, the Houthis, like much of their community, were primarily Zaydi. But in the immediate wake of reunification, they—along with their wider community—began to endure unwelcome visits by state-sponsored Sunni revivalists, preaching the word of a movement called Salafism.

A rapid influx of Salafist preachers was a threat to an old and sacred way of life. The Houthi clan started to revive their own Zaydi traditions within their communities, eventually building into an ideologically moderate movement that advocated religious tolerance, but sought to reinforce Zaydism in traditionally Zaydi communities. At the head of the movement was an organization called Believing Youth, founded by Hussein al-Houthi, alongside his brothers, Abdul-Malik and Yahia, and his cousin Mohammed.

In the early days, Believing Youth didn’t seem to be much more than an attempt to get young people into Zaydism in the Saada governate of Yemen, where the Zaydi community and the Houthis themselves are most highly concentrated. Hussein al-Houthi and his relatives had experienced persecution in the past, previously having been forced to flee to Syria and then Iran after supporting a South Yemeni separatist movement, but their immediate intent did not appear to be any broad political change to the Yemeni nation. Leaning on the father of the three al-Houthi brothers, who was himself a highly influential Zaydi cleric, the group set up school clubs and summer camps that drew thousands of young attendees.

Among the religious scholars they welcomed for their events was Hassan Nasrallah, who, by then, was already the Secretary-General of the Lebanese organization Hezbollah. But while Believing Youth didn’t appear to desire regime change, they certainly had their grievances with the ruling Saleh government. Saleh, they said, was deeply and obviously corrupt, exploiting the Arab world’s single poorest nation and funneling what little wealth it had directly to himself.

Believing Youth took a stance opposed to Saleh’s openness to Saudi Arabia, a more powerful Arab nation that sent a steady stream of Sunni fundamentalists to try and change the nature of Yemen itself. And they were strongly opposed to the actions of the United States, a global superpower that had chosen to stand behind and support Saleh, despite his many flaws, because he could help to counter the al-Qaeda organization. Perhaps unsurprisingly, Saleh didn’t take kindly to such attacks, and the Zaydis, already marginalized under his rule, found themselves the target of wider-reaching persecution and discrimination.

In 2003, the Believing Youth got a front-row seat to an event that would change the entire Middle East forever. Almost precisely two thousand kilometers, 1,240 miles, from the Yemeni capital city of Sanaa, Saddam Hussein’s Baghdad and the entire nation of Iraq endured an invasion. The invading force was spearheaded by the Americans, the same global empire that the Believing Youth considered to be responsible for enabling, propping up, and protecting a dictator that the Believing Youth disdained.

Across the Arab world, the invasion of Iraq was a radicalizing incident for people watching from afar, and the Believing Youth were no different. They adopted a new name: Ansar Allah, or Supporters of God. Formally, they still bear that name today.

They adopted a new slogan: God is great, death to the US, death to Israel, curse the Jews, and victory for Islam.

Insurgency, Martyrdom, and Early Conflict

Very quickly, this largely peaceful movement had been so deeply embittered that, at least rhetorically, they were willing to stand up to the world’s most powerful nation. But around the world, almost nobody took notice. The world was changing too fast, there was too much going on all at once, and Yemen remained a place that even backwater countries referred to as a backwater country.

But one organization that did take notice of Ansar Allah was Hezbollah. In Ansar Allah, the Lebanese paramilitary saw something quite like themselves: a deeply angry rising movement, at least nominally under the Shia umbrella, with a set of common enemies and a deep loathing of a broken political system in their home nation. Before long, Hezbollah was sending liaisons to give Ansar Allah fighters critical combat training and expertise, rallying them to the example of a movement that had been where they were in that moment.

With Hezbollah came interest from the Iranians, and before long, Iran wasn’t just giving positive attention; it was giving money and weapons. Yet during these same critical months, Ansar Allah drew the fresh ire of Yemen’s leader, Ali Abdullah Saleh. The group was openly advocating Saleh’s downfall, and that simply couldn’t stand.

Saleh placed a large bounty on the head of Hussein al-Houthi, and accused him of attempting to set himself up as a Zaydi imam, staging violent protests, and more. Two days before the bounty was declared, over six hundred followers of Ansar Allah were arrested at the Great Mosque of Sana’a, Yemen’s capital city, and in that already fractious environment, the bounty and order to capture the movement’s leader would prove to be a bridge too far. The Ansar Allah movement was alleged, by Saleh, to have already been a rebellion prior to that moment—but if it wasn’t before, then it certainly became one.

What came next was brutal fighting, aimed at capturing Hussein al-Houthi, and after months of escalating firefights between the Yemeni government and Ansar Allah, the violent summer of 2004 concluded with the deepest possible blow to the rebel movement. Alongside twenty of his aides, Hussein al-Houthi was killed, in a series of cave hideouts close to the Saudi Arabian border. But to say that the Saleh government killed Hussein al-Houthi only tells half the story.

In truth, Yemeni soldiers didn’t just kill the man; they martyred him. From that moment forward, Hussein’s father Badreddin would serve as the group’s spiritual leader, which he did until dying a natural death in 2010, age 84. Hussein’s brother Abdul-Malik, alternately known to his followers as Abu Jabril, would become the leader of the rebellion, a position he still holds to this day.

His two surviving brothers, Yahia and Abdul-Karim, still lead beside him. And in a true testament, not just to the now-fallen Hussein’s value to the movement but his value as a symbol of resistance, the Ansar Allah movement would adopt a far more recognizable name in his honor: the Houthis. The death of Hussein would bring about a significant pause in the fighting between the Houthis and the Yemeni government, but that pause wouldn’t last forever.

In early 2005, a bit over half a year after Hussein died, the fighting picked back up again. About 1,500 people would die over the course of roughly two months, although the Yemeni government would significantly undercount the deaths going forward. Sensing that the situation could spiral out of control, Saleh attempted to offer the Houthis a blanket presidential pardon, but when he was greeted with the Houthis’ demands in return, both sides appeared to agree that any peace settlement was untenable.

Over the following years, the situation in Yemen would cycle rapidly, and repeatedly between periods of relative quiet, and periods of large-scale violence. The first half of the year 2007 was particularly bloody, with about 1,500 people killed over the course of the flare-up. Significantly, more government troops were killed than Houthis, and while the ceasefire that ended the flare-up would see a few Houthi leaders banished to Qatar, the movement was by no means diminished.

The Arab Spring and Tactical Evolution

In 2008, about a thousand government soldiers were killed over the course of a single month of fighting, along with triple that number injured, although the rebel death toll was unknown. In 2009, the Saleh government attempted a mass crackdown against the Houthis, using tanks and fighter aircraft to launch a large military offensive dubbed Operation Scorched Earth. During that stretch of fighting, the Houthis received arms and personnel support from Iran, and traded fire with Saudi Arabian security forces near the two nations’ lengthy shared border.

Eventually, the Houthis would accuse Saudi Arabia of having allowed Yemeni troops to attack from a Saudi base across the border, while in turn, the Houthis would accept help from foreign fighters, coming from Somalia. On the Yemeni government’s side, not one, but two prominent generals would be killed. Roughly eight thousand people would die during Operation Scorched Earth, including civilians and fighters on both sides.

And during those same months in late 2009, the Houthis would get their first taste of confrontation with a far more powerful enemy than they were fighting at home. After a cross-border ambush by Houthi fighters killed two Saudi Arabian troops, the Saudis retaliated at large scale, first with airstrikes, and then with direct assaults on a small mountain range where the Houthis had occupied a pair of Saudi villages. Two thousand Jordanian commandoes arrived to help the Saudis, along with a detachment from Moroccan special forces.

But despite their air power, despite their international support, and despite their far better training and equipment, the Saudis were pushed out of Houthi-controlled territory, suffering well over a hundred of their soldiers killed. By January 2010, it was the Houthis offering a truce to Saudi Arabia, and threatening all-out open warfare on Saudi territory if Riyadh disagreed. The Saudis ultimately took the deal, marking a symbolic victory for the Houthis that would have been unthinkable for their little movement, just a few short years earlier.

During these years, the Houthis learned rapidly about how best to take the fight to their adversaries, in a way that went above and beyond most non-state actors in the Middle East at that time. Even in the early years, the Houthis had operated asymmetrically, using twenty- to thirty-person teams to conduct frequent ambushes and hit-and-run attacks in the same way their grandfathers had done against European occupation. In the early days, the Houthis used all manner of terror tactics against their adversaries: taking hostages, executing sheikhs, beheading captives, and even executing the children of those who had wronged the movement.

But as time evolved, the Houthis got better, not just at fighting, but at avoiding acts that risked alienating them to people whose support they might one day need. By 2005, they were integrating assassination campaigns; by 2007, they were fortifying towns to resist government attacks, and raising units of nearly a hundred people to conduct concerted assaults on higher-value targets. By 2008, they were attacking supply lines and logistical infrastructure, destroying critical bridges, producing video propaganda, and using encirclement and envelopment in order to push the Yemeni military out of certain areas.

By 2009, they were going head-to-head with Yemeni brigades, operating in units of multiple hundreds, and launching raids into Saudi Arabia. 2010 saw more fighting between the Houthis and the Yemeni government, but this time, it wasn’t just the government that the Houthis would have to fight. Instead, they battled against other local tribes in northern Yemen, clashing along both ethnic and tribal lines. By then, they had carefully refined their approach to local combat; relying on alliances, tight networks of checkpoints, and carefully developed operational planning.

But the events of 2010, just like the events of every year until that point, were nothing in comparison to what was coming just a few short months later. The catalyst was a single event that took place three thousand kilometers, 1,800 miles, from Houthi territory, in the regional capital of Sidi Bouzid, in central Tunisia. There, a young man named Mohamed Bouazizi self-immolated in an act of protest against his government, setting off a series of collective actions that would topple Tunisia’s long-ruling dictator.

It was this action that kicked off the regional upheaval known as the Arab Spring, and in a country like Yemen, with a large armed resistance movement already poised for decisive action, the Arab Spring would prove too much for Yemen’s regime to bear.

The Yemeni Revolution and Expanding Control

By 2011, Yemen was an exceptionally poor nation, with low life expectancy, scarce education, widespread abject poverty, and much more. Alongside the Houthis, the government had been fighting al-Qaeda and a southern secession movement, while its people had developed strong community networks to rally and protest peacefully in the streets. Saleh was, by this time, in his sixties, and had ruled Yemen for over three decades, with rumors widespread that his own son, not even forty years old by that time, was going to take over in his father’s stead one day.

In the near term, Saleh was well on his way to making himself president for life, and was making overt threats to the country’s political opposition, knowing that despite the violence around the country, nobody could touch him in Sana’a without a reason for his enemies to unite. As it turned out, the Arab Spring was a fantastic reason to unite, and after a catalyst from another continent presented Saleh with a situation he’d never considered, it became very clear, very fast, that his entire house of cards could come tumbling down. At first, the protests were big, but not unmanageable in Sana’a; then, they spread outward to the other major cities of Yemen; and finally, they changed focus from a protest against the conditions in Yemen, to a protest against Ali Abdullah Saleh himself.

Within weeks, demonstrators at Sana’a University had drawn a crowd of ten thousand, and by a month later, the protests had swelled to ten times that size. Opposition leaders were calling for a national unity government, pro-Saleh tribal militias were instigating violent confrontations, and one by one, Yemen’s major tribes threw their support behind the uprising. The Houthis were very much among them.

Much to his chagrin, Saleh quickly learned that the protest movement was disinterested in a peaceful settlement that involved his personal, continued presence in Yemeni affairs. His advisors and top officials abandoned him, his backers in the United States abandoned him, and his regional governates abandoned him. The Gulf states tried to intervene and broker a peaceful exit for the dictator, but Saleh refused to engage with their efforts.

After the Yemeni opposition gave Saleh ample time to use the offramps in front of him, they eventually decided, in late May of that year, that it was time to take decisive action. Several days of heavy fighting in the Yemeni capital followed, elements of the military defected, tribal militias took over major locations in the country, the Yemeni government perpetrated a massacre against peaceful demonstrators, and despite the institution of a short-lived ceasefire, the situation devolved rapidly from there. On June 1, 2011, an assassination attempt left Saleh with a collapsed lung and burns over nearly half his body.

He was taken to Saudi Arabia, and wouldn’t return for several months. By then, Yemen was just barely a step short of all-out civil war, and in late November of that year, Saleh capitulated. He signed a document formally resigning, his deputy eventually became president unopposed, and from there, the situation only grew worse.

The Houthis didn’t play a leading role in the ouster of their longtime dictator, but it is critical to understand just what happened during the Yemeni Revolution, to understand that the Houthis themselves saw this period very differently. For the Houthis, the revolution had never been about enthusiastic participation in a national political process. Instead, it had created what is best described as a permissive environment, a situation where the Houthis could take unilateral action inside their own territory, while the government and most of civil society was distracted.

During 2011, they had done exactly that, seizing the city of Sa’ada as a base of operations, kicking out the local governor, and creating their own administration across the wider Sa’ada Governate. Then, they set their sights on another governate, al-Jawf, and after four months of fighting, they took that governate too. They fought fierce battles against Islamist groups and rival tribes, they conducted successful offensives in multiple other governates, and when President Saleh resigned, the Houthis rejected the deal that would transfer power to a new government.

The Fall of Sana’a and the Houthi Coup

In the fractured environment that was immediately post-revolutionary Yemen, it was highly unlikely that even an official peace would lead to the end of all fighting in the country—and the Houthis were a major part of the reason why. Just days after Yemen’s new president took the reins, the Houthis launched an offensive against Sunni tribesmen in the Hajjah governate, and killed a prominent military commander in another governate, Amran. Over the following months, Houthi forces would engage in numerous clashes against various adversaries, in bitter and mutually destructive affairs against other tribes that ultimately saw Houthi influence widen even further.

All the while, the Houthis spurned the peace process with the Yemeni government, despite offers that would have granted them limited autonomy in a pair of landlocked provinces. The group continued to gather and stockpile weapons, they continued to squeeze other tribes and religious groups out of the territory they controlled, and they received direct assistance from Iran and Hezbollah. By the summer of 2014, they were strong and well-organized enough that they could pose a mortal threat to the Yemeni government outright.

It is not unheard-of for rival groups to become strange bedfellows in times of conflict, but it was at about this time, the summer of 2014, that the Houthis welcomed the strangest bedfellow they possibly could have. That was the now-former dictator himself, Ali Abdullah Saleh, who had led and ordered long stretches of anti-Zaydi persecution, killed the Houthis’ iconic former leader, and done just about everything possible to alienate himself from the entirety of Yemen. But by 2014, Saleh and the Houthis had a series of common enemies.

Both strongly opposed the removal of fuel subsidies that had generated wealth for Saleh’s allies, and that the Yemeni public depended on, creating a wave of popular discontent that the Houthis were in prime position to capitalize on. Not only that, but a Sunni Islamist party seemed about to take the reins of government, something that stoked fear among just about every Yemeni who was not part of the Sunni Islamist movement. The Houthis needed Saleh’s political influence and the firepower that his military allies controlled; Saleh needed the bodies, the populist swell, and the strategic momentum that the Houthis could provide.

The moment to strike came on September 18, 2014, when Houthi forces marched on the Yemeni capital city of Sana’a. Three days later, the Houthis were deep inside the city, establishing control over its core institutions, as Saleh’s fighting units lent their support, and as the rest of the Yemeni Army chose to stand aside. Fighting alone and without military support, the Islamist paramilitaries couldn’t hold Sana’a, and before long, the Houthis had accepted a UN-brokered deal to form a new unity government.

For the briefest moment, despite hundreds dead across the capital, it looked as if the Houthis might have done it, finally leveraging their way into a political peace settlement that they could comfortably accept. Despite ongoing fighting, despite a suicide bombing that killed nearly fifty Houthi supporters, all sides were able to agree on a new Prime Minister, who was to take office and usher in the new government by early November. But just before that fragile coalition could take office, it fell apart.

Two days before the new government was to be sworn in, the UN Security Council announced sanctions against Saleh and two key Houthi leaders, accusing them of obstructing Yemen’s political process. In retaliation, Saleh’s political party stripped the sitting President, who was due to stay on through the transition because of a lack of a political successor, of all his party positions. Two days later, when the new government was sworn in, the Houthis refused to participate, and so did Saleh’s political party.

The Houthis blocked government appointments, stood in the way of official state business, and obstructed key individuals from doing their jobs. Things came to a head on January 18, 2015, when a group of Houthi fighters kidnapped the sitting President’s Chief of Staff, in order to force the new government to abandon its draft of a new constitution. The Houthis were asking for major changes to the fundamental structure of Yemen, advocating for a return to the two-halves state of affairs that had seen Yemen divided all through the Cold War.

A day later, the Houthis besieged the Prime Minister’s residence, and seized Yemen’s state TV and news agency. The day after that, pro-Houthi forces launched an all-out assault on the presidential palace, forcing the president to evacuate and eventually gaining complete control of the building. As the president fled through the capital, the Houthis prowled the streets and consolidated their control over critical state institutions.

They seized the president’s personal residence, where he eventually turned up, and they captured multiple military targets without a fight. The Prime Minister went into hiding, the government was forced to agree to a ceasefire, and finally, on January 22, the president and prime minister were forced by the Houthis to resign. After decades of building their power, years of taking and consolidating territory, and months of battle back and forth with the Yemeni government, the Houthi coup d’etat had proved unstoppable.

Civil War and Foreign Intervention

It was at roughly this moment, in the slow, grinding Houthi takeover of Yemen, that all hell broke loose. Although the Houthis had booted out the leaders of the Yemeni government, they hadn’t presented a clear set of leaders to immediately replace it, and while they could take the capital city by force, they certainly couldn’t lock down all of Yemen. Very quickly, a series of key events unfolded all across the country.

The leaders of major cities, especially in the Yemeni south, indicated that they would no longer take orders from Sana’a. Both pro- and anti-Houthi crowds turned out in the thousands in several critical cities, showing mass support to both sides of the unfolding crisis. Leaders of the long-running separatist movement in Yemen’s south announced that secession was finally underway, and when the Houthis attempted to hold a meeting with the other tribes and factions to establish a path forward, nearly every faction refused to show up.

The Houthis issued an ultimatum, threatening to take unilateral control of the nation if Yemen’s other groups didn’t work with them to create a unity government. After five more days of negotiations, the unity effort collapsed, and the Houthis did exactly what they’d promised. But the final catalyst to civil war came not from the Houthi movement, but from the recently resigned Yemeni president, Abdrabbuh Mansur Hadi.

After a month stuck under guard, he managed to slip out of his residence and get to the southern port city of Aden, far from Houthi control. There, in a televised address, he declared the Houthi coup to be illegitimate, and claimed that he remained Yemen’s constitutional president. Despite demands from his predecessor, Saleh, to go into exile, Hadi took control of a portion of the Yemeni military that remained loyal to him.

In Aden, a battle over the international airport brought about a victory for Hadi’s forces, and pushed pro-Houthi military elements to flee toward Sana’a. The Houthis bombed Hadi’s compound using captured warplanes in retaliation, although Hadi survived. A day later, four suicide attacks killed 142 people and injured 351 in Houthi-controlled Sanaa, in an attack for which the Islamic State took credit—but that motivated the Houthis to announce mass mobilization for a wider war effort against the Islamists, against al-Qaeda, against Hadi, and against all others who would use force to stand against their movement.

Hadi declared Aden to be Yemen’s temporary capital, the Houthis elevated a new and formidable military commander, and both sides began a massive battle over the city of Taiz. That battle is still technically ongoing via blockade, nearly a decade later, with about eighteen and a half thousand people confirmed dead so far. By now, it was abundantly clear to the world that Yemen, already a geopolitical dumpster fire, was now going the same way as Syria had done, when it spiraled into its ruinous civil war.

The Hadi government had requested an intervention, preferably led by Saudi Arabia, and with the US and Russia already bogged down in Syria, it fell to the kingdom in Riyadh to oblige. With Houthi forces rapidly closing in on Aden, time was of the essence, and Saudi Arabia announced the start of a coalition effort. Unlike the interventions in Syria and Libya, the Arab world would be taking care of Yemen itself, with Saudi Arabia joined by Egypt, Morocco, Jordan, the UAE, Qatar, Sudan, and several other nations in a joint land, sea, and air offensive in defense of Hadi.

The first phase of the coalition intervention was dubbed Operation Decisive Storm. Relying on US intelligence to guide their way, Saudi Arabia began a series of airstrikes, including Yemen’s largest airspace, which was, at that time, under Houthi control. Airstrikes pounded Yemen for weeks, attacking military headquarters, ammunition stockpiles, and other vital targets, while Saudi forces moved into position to deter Houthi fighters from attacking northward into Saudi territory directly.

They closed Yemeni airspace, and placed major naval assets in the Bab al-Mandeb Strait, a key entry and exit pathway to the Red Sea. But very quickly, the Saudi operation showed that, in terms of civilian casualties and collateral damage, it would be no better than the Western-led interventions elsewhere in the Middle East. Airstrikes registered in a refugee camp, on a school, and more, drawing major concern from the international community.

And despite the coalition’s clear control of the air, they proved incapable of stopping the Houthi advance on Aden. Bringing tanks and heavy artillery as part of their assault, the Houthis managed to recapture portions of the international airport, battled for the city center, and took complete, albeit brief, control of Aden’s new presidential palace. Despite a hammering from both naval ships and fighter aircraft, the Houthis were able to capture large portions of Aden, as the city devolved into a humanitarian nightmare.

The fighting was brutal, and despite a counterinsurgent air campaign that began in late March, it would take until July of that year for Hadi’s troops to take the airport back from the Houthis. They would take the rest of the city back shortly afterward. By then, the coalition operation had transitioned into its second stage, Operation Restoring Hope, although it’s not quite accurate to say that hope was ever restored to Yemen.

In reality, the coalition restored its airstrike policy after a brief pause, ravaging the capital, other key cities, and Houthi positions out in the countryside. The campaign hit schools and hospitals, drawing accusations of war crimes, and as the campaign continued, more and more Yemenis were displaced. Food was already in short supply in the country, and with the coalition targeting air and sea ports on a large scale, it became nearly impossible to get more aid into the country.

The Humanitarian Toll and Battlefield Adaptation

The Houthis continued their assault, purportedly shooting down American-made warplanes as they took more and more territory, and the Saudi-led coalition was bombing UNESCO World Heritage Sites and completely leveling hospitals operated by Medecins Sans Frontieres. According to UNICEF, that hospital was the thirty-ninth to have been hit by the fighting, to that point. The coalition would continue to cause mass civilian casualties, destroy aid routes, devastate critical infrastructure, and draw fierce worldwide condemnation, for several years.

During that time, Saudi Arabia and the United Arab Emirates would take unprecedented casualties, and lose considerable proportions of their equipment, including several valuable aircraft. The conflict also saw direct, on-the-ground involvement from the American firm Constellis, then known as Blackwater, including the loss of many dozens of their troops. Within a year or two of the start of the civil war, millions upon millions of Yemenis had been displaced, with well over half the population in desperate need of humanitarian assistance.

This is a place where malnutrition and poverty were widespread before the civil war began, meaning that when humanitarian aid routes were devastated and millions were internally displaced into dangerous areas with limited infrastructure, it took no time at all for the civilian population to reach the brink of famine. Even today, in 2024, the UN High Commission on Refugees states that six million Yemenis live on the brink of famine, and 17.3 million are acutely food-insecure. That is today, in an environment where it’s at least feasible to deliver aid—something that wasn’t true at the height of the civil war.

With mass poverty and mass displacement has come the spread of disease, the collapse of education and social services, and much more. After early 2016, the battle lines of the Yemeni Civil War frequently morphed and changed complexion, but the overall rhythm of the conflict remained consistent. Houthi fighters conducted large-scale offensives and endured large-scale counteroffensives, in rapidly tangling and untangling engagements with the Yemeni military.

Both sides are backed by a range of allied militias, who interact with the main factions in complex and often unpredictable ways. Al-Qaeda have been a major third force in the conflict, capturing numerous towns and cities at varying times, while suicide bombers by way of al-Qaeda, the Islamic State, and other militant groups have ravaged Houthi and government populations alike. The Houthis launched massive drone and missile attacks on Saudi oil fields and refineries, as well as Saudi military targets, and they gained another reputation for a series of successful shoot-downs of American armed drones.

That shoot-down streak continues, to this day, and the Houthis have also drawn America’s ire in another way, seizing its embassy and capturing its Yemeni-national staff in late 2021. In late 2017, Ali Abdullah Saleh met his end at the hands of his enemies-turned-allies-turned enemies, caught and killed in a Houthi ambush two days after he announced his split from the movement. In 2018, the city of Aden was overtaken by southern separatists, kicking the Hadi government out and gaining the support of the United Arab Emirates, now operating at cross purposes with the Saudi-led coalition.

The Houthis watched the deaths of many of their leaders, weathered allegations over the use of torture in their prisons, and killed or captured many hundreds of Saudi Arabian soldiers and allied fighters in battle. As they fought, they helped rewrite the rules of modern warfare, integrating consumer-drone technology to the battlefield a half-decade before the power of those drones were revealed to the world in Ukraine. And year after year, the Houthis learned their own hard lessons on the battlefield, elevating their combat prowess and finding creative ways to avoid both the Yemeni government and the Saudi coalition.

They learned to operate in a highly decentralized way, not just making autonomous decisions, but intentionally concentrating only small numbers of troops across each battlefield, while maintaining dozens or even hundreds of battlefields at once. They built elaborate, explosion-resilient trench systems, hid bunkers and arms caches in forested areas and near no-target infrastructure like hospitals and schools, and learned to use exclusively low-emissions phones to avoid being targeted. They weaponized the ability to stay in hiding spots for extreme lengths of time, even as a group, and developed rocket-powered canisters to get food to vulnerable outposts.

They learned to blend in seamlessly with the local population, always ready to break up larger fighting units into bands of no more than five well-disguised fighters. The positions they mean to defend are cloaked within interlocking defensive minefields, weapon emplacements, and more, set up in a way that even a single fighter could conduct a multi-stage defense all by himself, falling back from one set of machine guns and mortars to the next, and the next, all laid out in advance. Finally, the Houthis have mastered not just defensive, but offensive mine-laying warfare, especially against Saudi Arabia.

Over nearly two decades of constant fighting, the Houthis have become a deeply unconventional force, able to bridge the gap between asymmetric insurgent tactics and territorial control tactics in a way that few organizations, across time, have ever figured out. Faced with the reality of a Houthi adversary they could not defeat, in 2022, the many warring parties in Yemen were able to find their way to a truce. By then, about eighty percent of all Yemenis were reliant on foreign aid, the country’s economy was a smoking heap of rubble, and even the most basic services were all but nonexistent in much of the country.

The Houthis had taken major territory over the course of the war, and consolidated their authority over a massive stretch of land that has since become their power base, but they had pushed as far as they were able, without risking a complete collapse of society in the places they did control. For the forces fighting against the Houthis, the situation was no better. Saudi Arabia had lost its appetite for intervention, and both sides had major interest in a prisoner swap.

In April of 2022, the two sides agreed to a two-month truce across the nation; in June, it was extended by another two months; and in August, it was extended again. When it finally lapsed, no party to the conflict chose to restart hostilities at scale, and none have, ever since. Negotiations to formally end the war began in April of 2023, after Iran and Saudi Arabia reopened their diplomatic relations.

The Global Maritime Crisis and the Future of Yemen

At the time of writing, despite scattered continuing violence, the main battle lines of the Yemeni Civil War have yet to flare up again. No peace deal has yet been signed. With the bulk of the fighting now seeming to be over, it is worth stepping back and really understanding the scale of the devastation that the Houthis and their adversaries wrought against their shared nation.

According to the United Nations, at least 150,000 people died in combat during the seven years of full-scale warfare. Over 227,000 more people died during that same time, as a result of starvation, disease, and other factors that were inextricably related to the war. According to Save the Children, 85,000 Yemeni children had died of starvation in the country by 2018, while the UN states that 11,000 children are known to have been killed or wounded directly in the fighting.

The death toll from Saudi Arabia’s air campaign alone is estimated by the Yemen Data Project at over nineteen thousand civilians killed or injured. Millions of people were internally displaced across Yemen, and many of them are still displaced today. In 2024, the map of control in Yemen hasn’t changed much, but the country is just as much a patchwork as modern-day Syria, Libya, or Myanmar.

While the Houthis don’t control the entirety of the country, or even a majority of its physical territory, they do control most of the significant population centers, and a significant majority of all Yemenis living in the country. Other than a few isolated pockets, the Houthis control the entirety of what used to be the Yemen Arab Republic, during the years of the Cold War. They control hundreds of kilometers of Red Sea coastline, as well as many of Yemen’s outlying islands.

The internationally recognized Yemeni government exerts direct control over small pockets of territory, near the contested city of Taiz and in the far northwest corner of the nation, as well as a much larger portion of the country’s largely uninhabited eastern half. Three major non-government entities, all of them allied with the internationally recognized government, control pockets of territory along the Yemeni coastline. The largest of the three, the Southern Transitional Council, is still a secessionist movement like it’s always been, although it isn’t actively fighting to secede right now.

Al-Qaeda still holds small patches of territory, and its estimated two to three thousand surviving fighters are scattered across the landscape. The Houthi rebels are no longer centered exclusively in Zaydism. They haven’t been for quite a while, after long years of cooperation with Hezbollah and Iran have led some more mainstream-Shia ideas to strongly influence the group.

They’re not revivalists for the old Zaydi imamate, at least not publicly, and they’re neither uniformly popular among the Zaydi community, nor uniformly unpopular among Sunni Muslims. Their ideology has been described as highly politicized, but substantially simplified, with a lot of the traditional nuances of the Zaydi faith scrubbed out, to make the movement broadly accessible and focused on enacting change within Yemen. They’ve also devoted increasing proportions of their time to attempts to convince the world of the fundamental rightness of their answer, to one key question: Who controls Yemen?

After all, whoever is recognized as Yemen’s leader gets all the perks: a seat at the UN, a large state apparatus to work with aid organizations, the ability to really engage in international diplomacy, and much more. For the Houthis to be recognized internationally, or even globally, as the rightful power that leads Yemen, would be the ultimate, victorious end to their revolutionary movement. And, in some ways, they’re the right answer to the question.

Certainly, they exert the most authority over the most Yemenis; they hold the greatest relative military power, and there’s a good argument to be made that if international humanitarian groups could engage with them, at large scale, in good faith, then mass suffering across Yemen could be alleviated. To that end, current Houthi leaders have gone out of their way for years to present themselves as unifying, stately figures despite the realities of the civil war. All the while, they take an inconsistent mix of socially restrictive and socially permissive positions toward ordinary Yemenis, and work alongside the nation of Iran, without swearing allegiance to it.

They operate a very well-developed political propaganda machine, they’re savvy users of social media to spread their message, and they’ve relied on many of the same leaders for multiple decades now, despite the risks to their lives during the civil war. While they’ve garnered a well-deserved reputation for violating human rights during war, including the use of child soldiers, the widespread abuse of women and girls, and the use of civilians as human shields, the Houthis’ leaders often present themselves as having been disconnected from those decisions. Militarily, the Houthis are among the most well-armed non-state actors on planet Earth, bringing to bear not just stockpiled weapons, but production lines to replenish them.

The Houthis are largely reliant on short- and medium-range missiles and unmanned flying drones, both of which they can produce at large scale, mostly in-house. They’ve also received continual shipments from their backer Iran, including very dangerous ballistic missiles. Over the course of hostilities against the Yemeni government, the Houthis have captured several dozen tanks, hundreds of artillery pieces and heavy weapons, and even a few aircraft, although their status now is unclear.

They receive military support, not just from Iran but very recently from Russia, and in both 2019 and 2024, they were alleged by South Korea to have accepted weapons from North Korea. But if people around the world know the Houthi rebels for just one thing, then almost certainly, it’s the Houthi campaign against global maritime trade, capitalizing on the critical trade route located immediately off their western coast. For a bit over a year, at the time of writing, the Houthis have used cruise missiles, ballistic missiles, unmanned aerial drones, and explosives-packed sea drones to launch direct attacks on ships headed to and from the Suez Canal, one of the single most vital locations to the entire global economy.

To hear the Houthis themselves tell it, their objectives during the ongoing Red Sea Crisis have been simple. After the October 7, 2023 attacks by the Hamas terror organization against Israel, the Houthis expressed solidarity with Hamas, a fellow insurgency that shares a critical common backer in Iran. After launching a few handfuls of drones and missiles in Israel’s direction, without much success, the Houthis changed tactics.

In mid-November of 2023, they hijacked a cargo ship and brought it back to one of their own ports, and from then on, their missile and drone campaign against maritime trade vessels has been underway. Dozens of ships have been hit, several people have been killed, multiple vessels have sunk or been entirely incapacitated, and a combination of physical risk and heightened insurance prices has forced much of the Red Sea’s regular trade traffic to take a far longer route around the African continent. The Houthis have maintained that their target list is made up of vessels with a direct connection to Israel, and that their purpose is to place pressure on Israel that will force a ceasefire in Gaza.

However, many of the Houthis’ targets have had little to no connection with Israel or Israel-based companies. As maritime trade has come under threat, the world has been motivated to respond, but this time, it’s a US-led coalition that’s been learning the same lesson that Saudi Arabia’s coalition did. The Houthis are a very difficult force to stamp out, they’re highly resilient against the pressure of an air campaign, and they’ve got ample hiding spots for their heavy munitions.

Despite a range of US and coalition warships out on the Red Sea, despite a smaller number of trade vessels for those warships to protect, despite a long bombing campaign, and despite major symbolic strikes by American B-2 stealth bombers, the Houthis have continued to attack trade ships. Not only that, but they’ve become better at hitting Israel with missile and drone strikes, slipping through or partially circumventing Israeli air defense. The future of the Houthi movement is not written in stone, but it’s entirely likely that the future of the Houthis will be the future of Yemen.

Earlier in their history, the Houthis formed a movement that didn’t seem to intend to conquer all of Yemen, but now, much of the country is within their grasp. How they consolidate their newfound power, it’s difficult to say for sure, but it would take a far greater force to push them out of Yemen than either the Yemeni military or the nations of the world have been able to bring to bear. Until, and unless some major upset takes place, it’s the Houthis who will hold true power in Yemen.

The question of how long that power endures may simply be up to them.

Frequently Asked Questions

Where did the Houthi movement come from?

The Houthis originated as the Believing Youth, a Zaydi revivalist movement founded in northern Yemen in the early 1990s by Hussein al-Houthi and his brothers to counter a flood of Saudi-sponsored Salafist preachers threatening traditional Zaydi practices. The movement radicalized after the 2003 U.S. invasion of Iraq, adopting the slogan “God is great, death to the US, death to Israel, curse the Jews, and victory for Islam” and renaming itself Ansar Allah. The 2004 killing of Hussein al-Houthi by Yemeni government forces turned him into a martyr and transformed the group into a militant insurgency that took his name.

How did the Houthis seize control of Yemen’s capital?

By 2014, the Houthis had accumulated years of battlefield experience and formed a tactical alliance with their former enemy, ousted president Ali Abdullah Saleh, who contributed political influence and military allies. On September 18, 2014, Houthi forces marched on Sana’a; three days later they controlled the city’s core institutions, with Saleh’s units providing support and much of the Yemeni Army standing aside. By January 2015, the Houthis had besieged the prime minister’s residence, seized state television, assaulted the presidential palace, and forced both the president and prime minister to resign, completing their coup.

Why did Saudi Arabia intervene in Yemen?

After the Houthi coup and the flight of President Hadi to Aden, the internationally recognized Yemeni government requested military assistance. With Houthi forces rapidly closing in on Aden and the prospect of a fully Houthi-controlled Yemen on its southern border, Saudi Arabia assembled a coalition including Egypt, Morocco, Jordan, the UAE, Qatar, and Sudan and launched Operation Decisive Storm in March 2015. The conflict became a protracted war that lasted years, causing massive civilian casualties, destroying hospitals and infrastructure, and producing one of the world’s worst humanitarian crises, with six million Yemenis on the brink of famine by 2024.

How did the Houthis become such an effective military force?

Over nearly two decades of fighting, the Houthis evolved from a small group conducting simple ambushes into a sophisticated asymmetric force. By 2008 they were attacking supply lines and using encirclement tactics against Yemeni brigades; by 2009 they were repelling Saudi incursions across the border. They mastered decentralized command, elaborate explosion-resilient trench systems, integration of consumer drones years before Ukraine showcased their power, and offensive mine-laying operations. Iran and Hezbollah provided critical training, weapons including ballistic missiles, and tactical expertise throughout this evolution.

What is the Houthi Red Sea campaign, and why does it matter globally?

From mid-November 2023, in response to the Israel-Hamas war, the Houthis began attacking commercial ships in the Red Sea, claiming to target vessels linked to Israel as pressure for a ceasefire in Gaza. Using cruise missiles, ballistic missiles, aerial drones, and explosive sea drones, they struck dozens of ships, sank or incapacitated several, and killed crew members. The campaign forced much of global maritime trade to reroute around the African continent, dramatically raising shipping costs and transit times. Despite a U.S.-led naval coalition and sustained airstrikes including strikes by B-2 stealth bombers, the Houthis continued their attacks and improved their ability to hit Israeli territory.

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