It seemed clear from the outset of the Middle East war that the Houthis were never resolved to stay out of the fight; rather, their delayed entry reflected a calculated decision taken in coordination with Tehran. The question, as the Houthis themselves framed it, was not whether to join the fray, but when. 

Iran has aimed to stretch out a war of attrition with its enemies, making the battlefield ever wider, and using its assets incrementally as the confrontation unfolds. For some time, it appears, the Houthis believed that Iran’s strategy – attacking Israel, U.S. assets and Gulf oil and gas facilities, as well as blocking the Strait of Hormuz – was sufficient. Their own media narratives portrayed Iran as capable of winning the war. So long as Iran was holding the upper hand, why join the fight? Yet the Houthis always said they might enter the battle themselves, even without an explicit request from Tehran, if they perceived a meaningful deterioration in Iran’s position. 

Now, with U.S.-Israeli military pressure on Iran intensifying, they appear to have judged the moment ripe to step in. On the morning of 28 March, they launched a missile at Israel, crossing the threshold from declared readiness to active belligerency. They pledged to continue firing until what they called “U.S. and Israeli aggression” against Iran and other axis groups ends. 

The timing of their entry suggests two things. First, they may be seeking to bolster Iran’s negotiating position, amid growing talk of possible U.S.-Iran dialogue about ending the war. By opening another front, the Houthis increase pressure on Washington and its allies, signalling that if the U.S. and Israel do not halt their military campaign, its cost will keep rising. Secondly, they may be responding to mounting threats to Iran, including talk of U.S. marines occupying Iranian islands, other possible ground operations to try opening the Strait of Hormuz and the prospect of Gulf Arab states joining the confrontation. The Houthis have foreshadowed such thinking in various pronouncements since the war began. Late in the evening of 27 March, just hours before they fired at Israel, the Houthis released a self-described “important statement” setting out the conditions that would make them intervene: if other countries joined the U.S. and Israel in fighting Iran; if attacks on Iran or “another Muslim country” were launched from the Red Sea; or if the U.S. and Israel escalated the war. 

The Houthis’ choice of target is telling. By attacking Israel and, so far, no one else, they are telegraphing their capability while avoiding an immediate breach of an understanding they reached with Washington about the Red Sea. During most of the Gaza war from late 2023 to 2025, the Houthis were firing at shipping in the Red Sea and the Bab al-Mandab, the strait linking the sea to the Gulf of Aden, in solidarity with Hamas and the Palestinians. In January 2024, with President Joe Biden in office, the U.S. launched a bombing campaign in Yemen intended to stop those attacks and secure those vital shipping lanes. In March 2025, with the Houthis still harrying warships and merchant vessels with missiles and drones, the Trump administration escalated with a tougher 55-day bombardment. That May, the two sides made a deal whereby the U.S. would stand down and the Houthis would cease firing at the U.S. navy and commercial maritime traffic. These terms notably said nothing about Israel.

The Red Sea remains a latent pressure point. As demonstrated during the Gaza war, the Houthis can disrupt navigation in the sea and the Bab al-Mandab, with implications for global trade, particularly in oil and gas, that are even more severe with the Strait of Hormuz mostly shut. Iran has also made this broader maritime threat explicit. What had been touted as a deterrent is now brandished as a weapon. 

The Houthis share goals with Iran, but they also have their own risk calculus. They consider themselves an integral piece of Tehran’s “axis of resistance” to U.S. and Israeli hegemony in the region. They know that entering the war will expose them to attack. But staying out any longer would have raised a different kind of vulnerability, the prospect of their main patron being so severely weakened that it could no longer sustain them with arms and intelligence.

In effect, the Houthis are opening a controlled front: indicating readiness to escalate further if needed, while holding important forms of leverage, especially fire at Red Sea shipping, in reserve. This calibrated entry into the war strengthens Iran’s hand while keeping the Houthis’ own hand close to the vest. The question now is how far the Houthis are prepared to go and what they are ready to risk.

The Houthis took significant hits from 2023 to 2025, but they are far from a spent force. The U.S. bombing under Biden and Trump destroyed many of their military installations. For its part, Israel carried out dozens of airstrikes in Yemen between July 2024 and October 2025, targeting the Houthis’ weapons stockpiles and killing several of their senior military officers. What protected the Houthis from utter ruin was that much of their arsenal is hidden from aerial view in mountainous terrain. Thus, they were able to keep part of their advantage in asymmetric warfare, using missiles and drones, including unmanned underwater vehicles. While U.S. and Israeli strikes may have degraded that capability, they did not knock it out, meaning that the Houthis can still apply pressure in the Red Sea and Bab al-Mandab, where a single attack on an oil tanker can keep most commercial vessels stuck in port. Even before the Houthis got involved in the war, and despite their May 2025 deal with Washington, major shipping companies, including Maersk, CMA CGM, Hapag-Lloyd and MSC, had been largely avoiding the Red Sea due to what they perceived as the risk of Houthi attack. 

The group also has been quietly rebuilding since the Gaza ceasefire in October 2025, when it halted its attacks on vessels in the Red Sea (as well as its missile and drone fire at Israel). It expanded arms production in Yemen, and smuggling networks, many of them tied to Iran, have kept outside supplies flowing into their armouries as well. Sources in Sanaa suggest that, for weeks before launching their first missile at Israel, the Houthis were stepping up drills for missile and drone units and running naval exercises along Yemen’s western coast. They clearly wanted to be ready for renewed conflict when the time came. They are also more than prepared to portray any additional military setbacks as a political victory at war’s end, especially if Iran does the same.

The Houthis are aware that their involvement in the war risks losing important gains. One is the May 2025 understanding they reached with the U.S. over the Red Sea. The Houthis, for now, have not broken that agreement, as they have not fired on shipping – though of course they might do so. Another is the informal truce they struck in 2022 with Saudi Arabia, which heads the Arab coalition formed to oust them from power in Sanaa. That truce helped end the Saudis’ military campaign against the Houthis and stopped cross-border attacks by the rebels themselves on Saudi Arabia. Talks meant to cement this ceasefire – and eventually to include the Houthis’ Yemeni opponents – are on indefinite hold, following the movement’s Red Sea campaign in 2023-2025. They could collapse if the group decides to include Saudi Arabia among its targets.

According to people in the movement, several factors have been shaping the Houthis’ thoughts about these subjects. On a broader level, they viewed the decision of whether to get involved in the conflict as a matter of survival for both Iran and their own movement. Their statements suggest they believe the U.S.-Israeli war aims to defeat not just Iran but also the entire “axis of resistance”. The weakening or breakdown of that alliance would leave them exposed. On this point, Houthi-aligned sources have told Crisis Group, leaders and commanders are unified. 

In terms of their narrower interests, however, the Houthis must now weigh whether the cost of their intervention may exceed what they suffered during the Gaza war. Two dangers stand out. The first is that their May 2025 agreement with Washington could fully unravel. The second is economic. The group is already under severe strain due to U.S. sanctions; a wider conflict is likely to heighten these pressures. They absorbed the costs of confronting Israel over Gaza, but it remains unclear whether they can sustain the blows of a much larger war.

The Houthis also need to take the home front into account. Their decision to intervene may prove more difficult to justify than in 2023-2025, particularly if they renew a Red Sea offensive in support of Iran. During the Gaza war, the group was able to tap into the strong solidarity with the Palestinian cause that is deeply embedded in Yemeni society. Framing further destruction in Yemen as being in service of the Islamic Republic would be a harder sell. 

Cognisant of this problem, Houthi leaders have begun to frame their position through two main arguments. First, they say the U.S. and Israel attacked Iran because Tehran has championed the Palestinian cause and actively backed non-state actors across the Islamic world that oppose Israel; support for Iran thus means, by extension, support for Palestine. Their 27 March statement re-emphasised this point, portraying Iran, its allied militias and Palestinian militants like Hamas as one front. Secondly, they emphasise what they say is a historical relationship between Yemen and Iran, presenting it as a partnership in which each side has consistently stood by the other. That the Houthis chose to enter the war by attacking Israel likely reflects the continued importance of appealing to their domestic audience.

Still another factor the Houthis must consider is whether provoking Saudi Arabia would be worth the cost, particularly if they attack Saudi interests. Angering Riyadh could put an end to the permanent ceasefire talks, which are already frozen, raising the possibility of renewed fighting with the Arab coalition and its Yemeni allies. These negotiations also have an economic component: they are meant to secure Saudi financing for payment of public-sector salaries in the Houthi-controlled areas of Yemen. Many civil servants in these areas have gone unpaid for years. Yet, vital as these economic considerations are, the Houthis regard them as secondary to the existential threat that might face Iran and the “axis of resistance”. 

The Houthis could also use the stalled talks with Saudi Arabia as an additional justification for escalation. Already, they have increasingly been depicting the economic crisis they face as part of a Saudi-U.S. effort to weaken them. On 26 March, the eleventh anniversary of the Saudi-led coalition’s intervention, both Abdul-Malik al-Houthi and the head of the Houthis’ Supreme Political Council, Mahdi al-Mashat, warned Riyadh that delays in honouring prior understandings would carry consequences, signalling that they will not wait forever for negotiations to resume. This messaging also seems aimed at Yemenis: having now entered the war, if the Houthis open additional fronts, they will cast their actions not merely as coming to Iran’s aid, but also as responding to local grievances with Saudi Arabia.

But what has most informed Houthi calculations may well be their belief that restraint would not have guaranteed their safety. On the contrary, they think that the U.S. and Israel will eventually go after them, regardless of whether they intervened on Iran’s behalf, and that being the last axis member standing could make them particularly vulnerable. The question then becomes one of timing: entering the war will bring immediate costs, but holding back might have posed delayed but more dangerous medium-term risks. The Houthis’ decision to fire at Israel suggests they have opted to pay the near-term costs rather than court greater danger later.

The Houthis may be betting on an outcome in which Iran pushes the U.S. and Israel to seek a diplomatic way out, with the Islamic Republic selling its mere survival as a triumph. In this optimal scenario for them, they would preserve their strong position in the axis as well as their value as an active deterrent force, rather than one held in reserve for a future conflict.

For now, the Houthis are launching missiles and drones at Israel, without engaging on other fronts. What comes next will largely depend on how the larger war evolves, how much more the U.S. and Israel step up attacks on Iran and how the U.S. and Israel respond to the Houthis’ actions. If the conflict intensifies, the group is likely to expand the scope of its attacks.

As noted above, the Houthis might resume attacks on vessels in the Red Sea they have linked to Israel or the U.S. Their maritime campaign would probably spread quickly into the Bab al-Mandab and Gulf of Aden, increasing the hazards, and thus the costs, for commercial shipping. The effect on global trade would be immediate, especially for energy flows, seeing as it would come on top of Iran’s blockage of the Strait of Hormuz. The Houthis could also intensify their fire in the northern part of the Red Sea, especially since Saudi Arabia is rerouting its oil exports from the Gulf via the east-west pipeline to its Red Sea port of Yanbu and directing oil tankers to the Suez Canal instead of the Bab al-Mandab. Disabling that pipeline, which runs underground, would be hard, but the Houthis might try it. 

Another escalatory move might be to hit U.S. military bases and logistics hubs in the Gulf, or even to attack Gulf Arab states themselves, as the Houthis have done in the past, on the stated grounds that these countries are directly or indirectly supporting the U.S. war effort. Should the Houthis take this step, they would be complementing Iran, putting extra pressure on Washington and anyone joining a U.S.-led campaign to reopen the Strait of Hormuz. The group has already declared Iranian strikes on Gulf Arab states to be a legitimate response to the U.S.-Israeli attack on Iran based on the fact that these countries host U.S. military bases.

The Houthis are unlikely to do these things all at once. They usually calibrate their actions, probing and applying pressure, then adjusting based on the resistance they encounter. It is a risk management strategy. Afterward, they may ramp up attacks in ways that are hard to predict or contain. In their campaign against shipping during the Gaza war, they escalated in phases, steadily increasing the scope and sophistication of their attacks over a period of two years. Whether they can do the same again likely depends on whether Iran can still supply weapons and intelligence to the group. 

For, much as they have rearmed, the Houthis face significant constraints related to their weapons stockpiles. Entering the war is likely to entail a prolonged confrontation, requiring sustained use of missiles, drones and other weaponry, which could gradually deplete their reserves. This risk is compounded by uncertainty around resupply. If military pressure on Iran intensifies in parallel, Tehran may struggle to maintain the steady flow of arms it has provided in recent years. 

Current developments nonetheless show that Iran retains some capacity to supply the group. Forces aligned with the internationally recognised Yemeni government reportedly intercepted a shipment of Iranian arms destined for the Houthis in late March, indicating that transfers continue despite the conflict. Still, should the war widen or Iran’s position weaken, maintaining such supply lines will become increasingly difficult. The Houthis would be left heavily reliant on their own stores. Over time, they might be weakened to the extent that their Yemeni foes would be emboldened to go back on the offensive. 

Neither Yemen’s internationally recognised government nor Saudi Arabia wants any part of what the Houthis’ choice may bring. But hoping to stay out of the mêlée and being able to stay out are two different things. The Yemeni government is already in a tough spot. Internal political challenges, economic strain and an unresolved conflict with the Houthis have left it with limited room to manoeuvre. The Yemeni government has condemned the Houthis’ decision to enter the war, warning of serious consequences. Further Houthi escalation would make things even more difficult, as it could increase pressure on the government to join the U.S.-led war effort, most likely by shoring up its positions around the Bab al-Mandab. The Houthis might not wait for its Yemeni adversaries to do so. They might move pre-emptively against government forces deployed in coastal areas in order to disrupt any military alliance with the U.S. before it can take shape.

Saudi Arabia is in an equally uncomfortable position. Its intervention in the Yemeni civil war since 2015 has been far lengthier and costlier that it anticipated – and the Houthis are undefeated. Riyadh was also forced to spend considerable political capital in its diplomatic efforts to nudge the Houthis toward negotiations in 2022 as a necessary condition to stop its military campaign against the group. The result has been relative calm in Yemen, though to Saudi Arabia’s regret not yet an intra-Yemeni peace deal that would allow it to end its involvement. A reignited war would put all this progress, however tenuous, at risk. At the same time, Saudi Arabia has its own security and economy to protect from Iranian attack. Riyadh’s instinct will be to keep lines of communication with Houthi leaders open and to try stopping the fire from spreading. Such a containment strategy obviously has its limits, however, and Riyadh may find itself pulled back into active participation against its better judgment.