BEHIND THE LINES: By joining Iran’s war, the Houthis have opened a dangerous new arena – one that could hit global trade, oil flows, and the wider regional balance.

On March 28, the Houthis organization (known also as Ansar Allah), which controls around 30% of Yemen’s territory and governs the majority of the population, joined Iran’s war against the US and Israel. The organization launched two ballistic missiles at southern Israel. Both were intercepted.

In a statement issued after the attacks, the organization’s spokesman, Yahya Saree, said that “The Yemeni Armed Forces, with the help of Allah Almighty and relying upon Allah, have carried out the first military operation using a barrage of ballistic missiles targeting sensitive Israeli military sites in southern occupied Palestine.

“This operation coincided with the heroic operations carried out by our mujahideen brothers in Iran, and Hezbollah in Lebanon. By the grace of Allah Almighty, the operation successfully achieved its objectives.’

The decision by the Houthis to enter the fight (albeit currently in a less than total way) means that the entirety of the Iran-led regional alliance, with the notable exception of its severely damaged Palestinian components, is now engaged in the war against Israel.

Still, the most significant potential contribution of the Houthis to Tehran’s war effort has yet to be activated. During the course of the war in Gaza, the Houthis kept up a steady stream of missile and drone attacks on Israel. But while these did cause a civilian fatality, in Tel Aviv in July 2024, they were mainly relatively minor detail set against the backdrop of the much larger conflict taking place between Israel and Hamas/Hezbollah/Iran.

The far more consequential element of the Houthis’ activity at that time was the campaign of attacks on shipping passing through the Bab el-Mandeb Strait, between the Red Sea and the Gulf of Aden. Some 10%-12% of global maritime trade passes through this narrow strait.

The Houthis’ attacks on commercial shipping caused a 90% decline in traffic using this route during the Gaza War. Instead, shipping companies were required to reroute down to Africa and around the Cape of Good Hope.

The organization ceased this activity prior to the ceasefire that ended the Gaza War. It did so as a part of a separate ceasefire it reached with the US in May 2025, which did not include a commitment to stop attacks on Israel.

The Houthis do not control the southern coastal tip of Yemen adjoining the Bab el-Mandeb, but their area of control does stretch along a line of the Yemeni coast, down to and including the key port of Hodeidah. Control of this stretch of coastline brings shipping passing through Bab el-Mandeb within range of the Houthis’ missiles and drones.

Houthis joining war risks closure of crucial Bab al-Mandab maritime route

THIS CAPACITY is of yet greater consequence in the current context, because of the Iranian blocking of the Strait of Hormuz. With Hormuz effectively closed to commercial shipping, the Bab el-Mandeb route is increasingly relevant as an alternative route for ships seeking to transit from Asian waters to European ones.

The route is already being used in this way. Specifically, Saudi Arabia is using its east-west pipeline and its Red Sea port of Yanbu to transit up to 7m. barrels of oil a day via this route, according to a recent Reuters report.

The Hormuz closure prevented Saudi Arabia from moving 15m. barrels of crude that normally transited the strait. The east-west pipeline and Yanbu are thus playing a vital role in allowing Riyadh to move oil exports, even with Hormuz closed.

But the entry of the Houthis into the fight raises the possibility that the campaign against shipping on the Red Sea might recommence, preventing further safe use of this route. This would have grave implications for Saudi oil exports. The markets clearly took notice of this possibility following the Houthi attack on Israel on Saturday. Oil prices surged by 3% on Monday.

The Houthis have not yet begun attacks on tankers passing through Bab el-Mandeb. Nor have they declared a specific intention to begin such a campaign. An intervention of this kind, unlike the sporadic launching of projectiles against Israel, would be an extremely consequential move, and would with certainty bring down on the Houthis very severe retribution from both American and Israeli air and naval power. Is it likely to happen?

Much analysis of the Houthis in recent days has focused on the movement’s independent decision-making capacity. This is valid, but should not be exaggerated. The Houthis indeed belong in the category of clients of Tehran, rather than proxies. The distinction is significant.

The Houthis, like the Palestinian Hamas movement, are an authentic local movement resting on long local traditions and with a history outside of their relationship with Iran. Despite being Shi’ite (of a notably different brand than the Twelver Shia Iranians), they are neither the creation of, nor the tool of, the regime in Tehran.

This differentiates them significantly from organizations such as the Lebanese Hezbollah and Iraqi Kataib Hezbollah groups, which are franchises of the Islamic Revolutionary Guards Corps (IRGC) – established by, armed by, financed by, and ultimately controlled by Iran.

Although the Houthis undoubtedly maintain an independent decision-making capacity, it should also be understood that their outsize military capacities are the direct result of their relationship with the Iranians. Furthermore, Iranian and pro-Iranian Arab personnel are directly involved with Houthi military capabilities.

IRGC officers in Yemen, 'deeply involved' in supervising Houthis

According to documents obtained by The Jerusalem Post from Yemeni sources, IRGC personnel are present on Yemeni soil, and are deeply involved in supervision of the Houthis’ “intelligence, drone and missile capacities.”

The documents note the existence of a joint operations room responsible for these capacities, and detail the involvement of Iranian, Iraqi, and Lebanese experts in maintaining these capacities and in the training of Houthi personnel in both Lebanon and Iran, to equip them with the abilities to maintain and operate the relevant systems.

So the Houthis, while they indeed have separate origins and structures from Iran and the IRGC, are nevertheless deeply embedded within the region-wide military structure organized and led by Iran. The Houthis’ very ability to strike at their enemies, both within and certainly outside Yemen, derives from their relationship with Iran. It is not likely, therefore, that they would refuse a direct Iranian request to join the war by beginning attacks on tankers in the Red Sea.

This has not yet happened. Presumably, the Iranians want to keep this strength in reserve for the moment, perhaps calculating that the commencement of such attacks might lead to Saudi Arabia and the Gulf states drawing closer to the US and even joining the war on the US side.

It may well also be that Tehran prefers to keep the commencement of attacks in the Red Sea as a potential tool to be activated should the US and Israel escalate further, for example, in the event of US ground action to force the reopening of Hormuz.

Regardless, the firing by the Houthis of ballistic missiles is a significant additional step up the escalation ladder by Iran, opening up a fourth front in the war between Israel, the US, and Iran (the three open ones are the missile/drone war between Israel and Iran, the Israel-Hezbollah front in south Lebanon, and the Iraqi Shi’ite militias’ campaign against US and allied forces in Iraq).

This fourth front, if fully engaged, has the potential to inflict further severe damage on global supply chains, and consequently on the global economy. The Iranian side just raised the stakes.