The Houthis’ attack on Israel heralds a significant escalation in the war with Iran

The launch came hours after the Houthis, a Shia movement that is aligned with Iran and dominates northern Yemen, issued a communiqué on March 27th warning that they were poised to enter the war. Continued American and Israeli attacks on Iran would prompt “direct military intervention”, it said, as would other powers joining in America’s and Israel’s war. That appeared to be a reference to Saudi Arabia and the United Arab Emirates (UAE), the Houthis’ former adversaries in Yemen.

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For now, the Houthis have stopped short of using their most potent lever: their ability to disrupt shipping in the Red Sea. Since the closure of the Strait of Hormuz, Saudi Arabia has rerouted roughly 1.8m barrels a day of oil exports west to its Red Sea terminal at Yanbu. Were the Houthis to disrupt this vital artery by targeting either passing ships or pipelines and infrastructure at Yanbu while the Strait of Hormuz remains closed, analysts reckon oil could jump from its current price of around $113 a barrel to close to $200.

According to multiple Yemen watchers, this scenario is now more likely than when the war began. The Houthis have reinforced their positions along the Red Sea coast between Hajja and Hodeida ports and along the Saudi border. One observer says they have deployed “anti-ship missile batteries, naval sabotage teams, explosive-boat infrastructure, sea-mines and maritime-drone launch sites…capable of threatening Red Sea traffic”. “The Houthi command architecture is no longer in a deterrence posture,” says Nawaf Obaid, a Saudi analyst who runs a project at King’s College, London, that tracks regional signals intelligence. “It is moving into a strike-ready configuration.”

Although they are a part of Iran’s so-called “axis of resistance”, alongside Hizbullah in Lebanon and a slew of Iraqi militias, the Houthis largely sat out the first month of the war with Iran. That restraint was in stark contrast with the Gaza war, when they showed solidarity with Hamas by harrying Red Sea shipping bound for the Suez Canal. Despite increasingly anguished Iranian entreaties, they have been upholding a de facto ceasefire that followed America’s 52-day bombing campaign in spring 2025.

Early on, at least, the militia considered restraint to be in its self-interest. Israel’s killing of Hassan Nasrallah, Hizbullah’s leader, in 2024, and of Iran’s supreme leader, Ali Khamenei, at the outset of the Iran war, appeared to loosen the grip of Iran’s Islamic Revolutionary Guard Corps (IRGC). The Houthis seemed more focused on concluding a deal with Saudi Arabia. A Houthi delegation, headed by Muhammad Abdulsalam, their chief negotiator, reportedly went to Riyadh near the start of the war. Their aim seemed to be to win improved terms—perhaps Saudi funding for their salary bill or formal recognition of their hold over Sanaa. The reluctance of other states on the peninsula to join the war also made it more palatable for the Houthis to stay out of it.

Three factors appear to have shifted the calculus. Iran’s attacks on Gulf energy infrastructure, ports and commercial hubs are dragging the region into the fray. Increasingly, Gulf officials flaunt their own offensive capabilities. On March 27th the UAE announced plans for a multinational naval task force to protect shipping in the Strait of Hormuz. As Gulf states edge closer to joining America’s war, the Houthis appear to be drifting back towards Iran and Hizbullah. According to Mr Obaid, the IRGC is also positioning its own officers in Sanaa to co-ordinate Yemen’s response.

America’s military manoeuvres are also changing the Houthis’ threat perception. America is sending more troops to the region, perhaps in preparation for an amphibious attack on Iran’s islands in the Gulf. But it is also adding forces encircling the Houthis. The USS Abraham Lincoln, one of two American aircraft-carriers in the region, is now off Salalah, in Oman, near Yemen’s border. American forces have also bolstered their presence in Djibouti on the Red Sea and reportedly gained access to Saudi airbases such as Taif, some 500km north of Yemen.

But perhaps the biggest driver pushing the Houthis to escalate is the economy. Civil servants have gone unpaid for months. Some 18m Yemenis face acute hunger; most of them are ruled by the Houthis. Payments from Saudi Arabia have dwindled; the most recent, last autumn, was said to be worth $1bn, far short of the salary bill. Hopes of a bigger package have not materialised. In a speech on March 26th the group’s leader, Abdul-Malik al-Houthi, railed against Saudi stinginess. Houthi harassment of UN and aid agencies has choked off further international assistance. Revenues from taxing maritime traffic vanished with the Gaza ceasefire.

The Houthis are undoubtedly weakened, following America’s assault on its arsenal and the killing of much of its leadership by Israel last year. But that has not dented their inability to make themselves a nuisance. It would take only a handful of strikes to make the Red Sea in effect impassable, as insurers push premiums to prohibitive levels and risk-averse shipping companies order vessels to take longer routes. With dwindling resources and fresh leverage, the Houthis may yet decide to resume attacks on shipping. If they do, the consequences will ripple far beyond Yemen.