Foreign Affairs - The Middle East’s Most Overlooked Threat - How the Houthis—and a New Civil War in Yemen—Could Upend the Post-Gaza Balance of Power - April Longley Alley December 18, 2025

 Foreign  Affairs

The Middle East’s Most Overlooked Threat

How the Houthis—and a New Civil War in Yemen—Could Upend the Post-Gaza Balance of Power

April Longley Alley

December 18, 2025

Houthi fighters in Sanaa, Yemen, September 2025 

Khaled Abdullah / Reuters

APRIL LONGLEY ALLEY is a Senior Fellow at the Washington Institute and served as Senior Political Adviser to the UN Special Envoy to Yemen from 2020 to 2024.

Among the broader regional effects of the October cease-fire in Gaza, one of the more significant was supposed to be a new calm in the Red Sea and potentially in Yemen. Indeed, as a result of the truce, the Houthis—the heavily armed militant group that controls northern Yemen, including the capital, Sanaa, and is allied with Hamas and Iran—paused their attacks on commercial shipping in the Red Sea and against Israel. An earlier Omani-brokered agreement between the Houthis and the U.S. government also seemed to wind down the direct Houthi threat to U.S. assets in the shipping corridor. Within Yemen, a fragile three-and-a-half-year-old truce in the civil war between the Houthis and the internationally recognized government was still in place. Although the Houthis were not defeated, U.S. officials seemed to believe that the situation in the country had quieted and that they could turn their attention elsewhere.

Less than two months later, that relative calm is fading. In early December, southern Yemeni separatists launched a major campaign to seize large parts of the Hadramawt, an oil-producing region bordering Saudi Arabia, and Mahra, a province bordering Oman. The offensive by the Southern Transitional Council, a group that is part of the internationally recognized Yemeni government but advocates independence for southern Yemen, marks a seismic shift in the country’s balance of power. For one thing, the STC is backed by the United Arab Emirates, and its bold expansion has set off new tensions with Saudi Arabia, which supports competing factions within the government and views the takeover as a potential threat to its national security. Still more concerning, the STC offensive is likely to provide a pretext for larger actions by the Houthis.

Even as the STC campaign has unfolded, the Houthis have vowed to extend their own control over the oil- and gas-producing regions in the country’s east. With the help of Iran and other countries, the Houthis have also worked tirelessly to expand their arsenal of advanced conventional weapons; they have also scaled up domestic weapons production, with the capacity to assemble ballistic missiles as well as to independently manufacture short-range drones. Moreover, the group’s actions and rhetoric continue to underscore its desire to control all of Yemen and to continue to confront Israel, the United States, Saudi Arabia, and the UAE. If the Gaza cease-fire falters, the Houthis are ready to continue their Red Sea attacks, and now that they have seen how effective that campaign has been, they could restart it for other reasons in the future.

The United States ignores Yemen at its peril. Thus far, the Trump administration has limited itself to imposing sanctions on the Houthis, protecting the U.S. bilateral truce with the group, and hoping that Israel and U.S. partners in the Gulf will sort out any other issues on their own. The administration has also largely stepped away from supporting the government of Yemen and providing diplomatic leadership to end the civil war. 

But without a broader U.S. strategy, financial pressure on the Houthis may well backfire. Before the STC’s move in December, the Houthi leadership suggested it might seek to seize more territory or extort financial concessions from Saudi Arabia to gain more resources. Now the upheaval in the south has made the country more combustible, threatening to reignite a conflict that has until now played to the Houthis’ advantage. Any return to full-blown war would have reverberations across the Gulf and the Red Sea region.

AXIS OF DEFIANCE

As the dust settles from Israel’s war in Gaza, the Houthis are notable outliers. With Hamas decimated, Lebanon’s Hezbollah largely decapitated, the regime of Bashar al-Assad in Syria toppled, and Shiite militias in Iraq avoiding conflict with Israel, the other members of Iran’s once powerful axis of resistance are severely weakened. By contrast, the Houthis have been emboldened by the war in Gaza, which helped enable their leaders to harden the group’s ideological core, marginalize pragmatists, and reinforce their supporters’ belief that they are on a holy mission to liberate Palestine and upend a U.S.- and Israeli-dominated regional order.

The Houthis have derived tangible rewards from their defiance. By staying on a war footing, they have avoided accountability for rising poverty and for failing to pay public sector salaries in areas they control. They have also used the conflict to crack down on perceived enemies, narrow any room for dissent, and tighten their grip on power. Meanwhile, the group’s high-profile conflict with Israel has bolstered military recruitment, including of child soldiers, and facilitated its efforts to train and indoctrinate a new generation. As of 2024, the Houthis were estimated to have some 350,000 fighters.

The Houthi threat has been compounded by the group’s growing military capabilities. In the early phases of the war in Gaza, Houthi missiles were mostly unable to reach Israeli territory; by May 2025, they could hit Ben Gurion Airport outside Tel Aviv. In September 2025, Houthi drones were also able to evade Israeli air defenses, wounding more than 20 people in Eilat and hitting nearby Ramon Airport. Houthi missiles have also struck Yanbu, a major Saudi oil port some 620 miles from the Yemeni border. At the same time, the Gaza conflict has given the Houthis valuable operational experience, allowing them to improve the accuracy of their targeting and test new weapons, including ballistic missiles armed with cluster munitions.

To expand its arsenal, the group has diversified its supply chains and forged ties with a variety of U.S. foes, including China and Russia alongside Iran. For years, Tehran has supplied conventional weapons and training to the Houthis, and it has doubled down on this support as other parts of its vaunted regional axis have weakened. Yet the Houthis are now also importing dual-use components and military-grade material from China for use in domestic weapons manufacturing. In September, the U.S. Treasury Department sanctioned 32 Houthi-linked individuals and entities, including several based in China, for illicit fundraising, smuggling, and weapons procurement.

In turn, Russia has shared targeting data through Iran’s Islamic Revolutionary Guard Corps to help the Houthis hit Western ships, according to the Wall Street Journal. Moscow has also delivered oil to the Houthis through the Yemeni port of Hodeidah. And in Somalia, the Houthis have provided weapons and training to the Sunni jihadist group al-Shabab in return for cash and a potential partnership in disrupting shipping in the Gulf of Aden. Somalia has also become an important transit hub for weapons smuggled into Houthi areas.

The Houthis’ leader, Abdul-Malik al-Houthi, has made it clear that the group’s ambitions do not stop at Yemen’s borders. In fact, uniting the Islamic world against Western influence and Israel has been part of the Houthis’ core belief system since the group’s inception in the early 2000s—a mission that has been greatly amplified by the war in Gaza. Houthi has said that more rounds of fighting with Israel are “inevitable” and that Saudi Arabia and the UAE are puppets in the U.S.-Israeli regional project and traitors to the Palestinian cause. He now boasts that his movement is training more than a million mujahideen and that Houthi-dominated Yemen leads the Arab world in military production and manufacturing. Although the claims regarding weapons production are patently false, they serve to buttress the Houthis’ self-image as the leading Arab resistance force.

PRESSURE WITHOUT POLICY

As their profile has grown, the Houthis have taken some hits. Operation Rough Rider, an intense 52-day bombing campaign that the Trump administration began in March, destroyed many Houthi arms depots and manufacturing facilities, although the full extent of the damage remains unclear. And the U.S. decision this year to redesignate the group as a foreign terrorist organization has put economic strain on Houthi-controlled territories by cutting off their access to the international banking system.

Since the summer of 2024, Israeli bombardments have inflicted significant damage on Houthi-controlled areas, shutting down the north’s only international airport, destroying much of the port of Hodeidah, and wreaking havoc on Yemen’s electrical infrastructure. Israel has also targeted the Houthis’ leadership with some success. In August, an Israeli strike killed the prime minister and other members of the Houthi-controlled government in Sanaa, none of whom were core Houthi ideologues In October, the Houthis confirmed that their chief of staff, a key military strategist, had also been assassinated. Although these attacks have had limited success in reaching the group’s top leaders, they have forced them underground, slowed Houthi communications, and stoked rumors that others may also have perished.

The Houthis have been openly threatening Riyadh.

But Washington’s overall approach to Yemen is riddled with contradictions. For example, the administration’s bilateral truce with the Houthis in May offered a quick exit from Operation Rough Rider, which had already cost more than $1 billion and involved heavy military assets that were needed elsewhere. But it did not prevent the Houthis from continuing attacks on non-U.S. targets in the Red Sea or from flinging more missiles and drones at Israel. Nor did it provide a long-term strategy for protecting American interests in the Red Sea or the Gulf.

On the contrary, by allowing Washington to disengage politically and militarily from Yemen, the truce has given the Houthis an opportunity to escalate its battles against its internal and regional enemies at a lower cost. Compounding the problem, the Trump administration has suspended most humanitarian aid for Yemen, including in areas controlled by the Yemeni government that the United States is ostensibly supporting. In a country in which 24 million people—a significant majority of the population—require humanitarian assistance and more than 14 million are in acute need, this amounts to an enormous blow.

Meanwhile, by toughening sanctions and removing diplomatic off-ramps for the Houthis, the administration has closed any prospect of a negotiated peace deal for now. The United States no longer has a dedicated envoy to Yemen, indicating how far the country has fallen down Washington’s list of priorities. The administration does not support returning to the pre–Gaza war formula for a Yemeni settlement, which called for the Houthis to agree to a cease-fire and a political process in exchange for financial benefits including the payment of public sector salaries. Yet few in Washington are working to find an alternative path forward.

THE NEW POWER SCRAMBLE

With the new upheaval in the south, the United States and its Gulf allies could soon face a broader crisis. It is possible that the UAE and Saudi Arabia could work to limit the shock waves from the STC’s seizure of Hadramawt by agreeing on a joint effort to contain tensions within the Yemeni government. Such a deal might lead to a more unified front against the Houthis allowing for a revived exploration of a political settlement in Yemen or a push by these forces to take territory from the Houthis in the north ahead of potential talks. 

Already, the president of the STC, Aidarous al-Zubaidi, announced that the group’s “next goal must be Sanaa, peacefully or through war.” Any agreement whereby STC forces could support fighters along the Red Sea coast and the city of Marib to reclaim the north from the Houthis would be tough, likely involving guarantees for southern autonomy and possibly a referendum in the future. But none of this is possible until the immediate impasse in Hadramawt is resolved in a way that addresses Saudi Arabia’s security concerns.

Time may be running short. There is also a real possibility of fighting between government factions, which could help the Houthis make further military or political advances. If the STC were to declare independence—something it seems keen to avoid for now because few countries would extend recognition—it could prompt a realignment of northern forces against it.

Absent U.S. engagement, Saudi Arabia and the UAE will continue to back rival groups.

Even if the STC’s campaign does not reignite a larger war, the Houthis will soon need to relieve the economic pressure they are under. This would likely mean seizing more resources inside Yemen—for example, by capturing the oil-rich governorate of Marib east of Sanaa—or by coercing Saudi Arabia into offering new financial concessions. The Houthis have been openly threatening Riyadh, demanding that the kingdom move to definitively end the civil war, lift restrictions on the ports and airports, and pay war reparations for the damage caused by Saudi air strikes on the country between 2015 and 2022. The Houthis’ messaging, including the reposting of videos of their previous incursions into Saudi territory and attacks on Aramco oil facilities, underscores their willingness to use force.

Given their focus on domestic priorities and growing doubts about the U.S. security umbrella, the Saudis could well succumb to this pressure. Although a Houthi grab for more territory will face internal Yemeni resistance, Riyadh may hesitate to assist these anti-Houthi forces for fear of renewed attacks. Alternatively, with the Yemeni government’s position weakened by the STC’s moves in the south, the Houthis could seek territorial gains, for example by redoubling efforts to get government-aligned tribal leaders around Marib to switch allegiance to their side. Any of these paths would give the Houthis more resources to arm themselves for future battles with the United States and its partners, not to mention reducing any chance of an inclusive political settlement in Yemen.

Israeli leaders have vowed to punish the Houthi leadership for its brazen attacks on Israel, and the Israeli government has established a new intelligence unit focused on Yemen. If the Gaza cease-fire collapses, clashes between the Houthis and Israel will resume, which could distract the Houthis from other fronts and provide potential miliary opportunities for their Yemeni adversaries. Yet Washington cannot rely on Israel to handle the Houthi challenge.

The Houthis are far from Israel and firmly entrenched in mountainous terrain similar to Afghanistan’s. As Saudi and U.S. campaigns have already shown, the group cannot be defeated by aerial bombardment alone. What is more, Israel is deeply unpopular in Houthi-controlled areas, and further Israeli strikes, especially on civilian infrastructure, risk rallying ordinary Yemenis against a hated external enemy. Even if Israel is able to pull off additional high-level assassinations, it might produce a more hard-line Houthi leadership in Sanaa or a new scramble for power that could destabilize the region in new ways.

FROM THE GROUND UP

Washington’s desire to avoid getting entangled in a costly war in Yemen is understandable. Nearly two months of intense U.S. bombing last spring inflicted pain on the Houthis but failed to change their behavior or their hold on power. The new STC offensive highlights growing fractures within the coalition supporting the internationally recognized Yemen government and the dauntingly complex and shifting nature of the country’s domestic politics. But given Yemen’s strategic location on the Red Sea corridor and its proximity to Washington’s key Gulf allies, the Trump administration cannot afford a policy vacuum.

To prevent a broader conflagration, the United States will need to recommit serious attention to the country. Most urgently, the administration must press Saudi Arabia and the UAE to quickly de-escalate tensions in the south and come to a common approach to Yemen. This will be a precondition for effectively addressing the Houthis. At the same time, Washington must do more to help government-aligned Yemeni forces hold critical frontlines, including in Marib and along the Red Sea coast, to persuade the Houthis to compromise. Enhanced U.S. security guarantees to Saudi Arabia and the UAE can play an important role in this regard, providing assurances that if either country is attacked by the Houthis, the United States will assist in their defense.

Washington must also renew its support for a dedicated diplomatic track. Yemen has been at war for more than ten years, and the staggering toll on its population will have generational effects. The Houthis and indeed the country’s broader internal challenges cannot be solved through economic pressure or externally led bombing campaigns alone. Coercion is needed—especially on-the-ground political and military pressure from Yemenis—but off-ramps and diplomacy are equally important. To this end, the United States should coordinate with all the major stakeholders in the country—Yemenis, Saudi Arabia, the UAE, Oman, the UN, and others—to map out a revised settlement.

The Trump administration needs to recognize that the post-Gaza, Gulf-centric security order it seeks to build in the Middle East will not succeed if Yemen descends into chaos. In the absence of U.S. engagement, Saudi Arabia and the UAE will likely continue to back rival groups within the government coalition, deepening tensions between two key U.S. allies (that are also playing out in Sudan), expanding divisions among Yemenis, and creating opportunities for the Houthis—as well as other violent groups such as al-Qaeda—to take advantage. And that could result in renewed Houthi actions across the region.

Restoring calm to Yemen will not be easy, and the effort will need to include security guarantees for the Red Sea and for Gulf neighbors as well as address the STC’s demands for southern independence. It will ultimately require bringing the Houthis into a political process and refocusing their attention domestically by giving them a stake in a better future. A deal may well stall in the face of many competing interests. But doing nothing will be far worse, all but ensuring that Yemen’s problems continue to spill out into one of the world’s most vital shipping lanes and the greater Middle East. Washington does not need to lead in Yemen, but the stakes are too high not to show up.