Iran Watch Listen: How to Put Iranian Weapons Out of Arm’s Reach for the Houthis

March 27, 2024

Publication Type: 

  • Interviews and Podcasts

Weapon Program: 

  • Missile
  • Military

Related Country: 

  • Yemen

In this episode of Iran Watch Listen, we sat down with Wolf-Christian Paes, an expert on arms and maritime security who served on the U.N. Panel of Experts on Yemen from 2018 until 2023. We discussed Iran’s support for the Houthi rebel group, the ways in which arms are smuggled into Yemen, and the challenges of enforcing the arms embargo imposed on the Houthis by the U.N. Security Council—as well as what that bodes for the outcome of the current crisis in the Red Sea. The conversation took place on March 19 and was hosted by John Caves, a Senior Research Associate at the Wisconsin Project on Nuclear Arms Control, and John Krzyzaniak, a Research Associate at the Wisconsin Project. Read more about our guest below.


The Houthi movement, officially known as Ansarallah, emerged in northwestern Yemen in the 1990s as a Zaidi Shia revivalist movement and turned to armed insurgency in 2004. In 2014, the Houthis forcibly took control of the capital city Sanaa and displaced the government led by interim President Abdrabbuh Mansour Hadi, plunging Yemen into a full-scale civil war. In March 2015, a coalition led by Saudi Arabia began an air campaign to restore the internationally recognized government to power. Fighting between the coalition and the Houthis continued until April 2022, when the parties reached a truce agreement backed by the United Nations. Since then, the level of fighting in Yemen has drastically reduced, although negotiations toward a formal resolution remain ongoing.

Iran’s support for the Houthis can be traced back to at least 2009, when, according to a report by a United Nations Panel of Experts, Iranian smugglers first ferried weapons to Saada governate, where the group was headquartered. In those early years, Iran’s support likely remained limited. But after Saudi Arabia intervened in 2015, Iran provided the Houthis with the parts and know-how to assemble potent missiles and drones, and even to manufacture some of the components locally.

An infrared image of a dhow whose cargo was seized by U.S. Navy forces on January 11, 2024. (Credit: U.S. Central Command)

During the war, the Houthis used these weapons to attack Saudi Arabia and, later, the United Arab Emirates, as well as against the forces of the internationally recognized government in Yemen. Such attacks largely ceased when the truce was agreed in April 2022. But the Houthis turned to their strategic arsenal once again in the fall of 2023, in response to the Israel-Hamas war in Gaza. Since November, they have launched missiles and drones towards Israel and have used those weapons to attack commercial ships transiting the Red Sea and exchange fire with the U.S. Navy and its allies.

Our Discussion

The Houthis have received multiple groups of Iranian-sourced weapon systems, according to Paes. This includes systems that form the backbone of their “strategic arsenal” of cruise and ballistic missiles and drones, as well as anti-tank guided missiles, small arms and light weapons, and ammunition. Based on the result of interdictions, Paes assessed that the Houthis’ missile manufacturing capability has improved over time: whereas the group used to smuggle components for complete missile systems, there has been a more recent trend towards smuggling spare parts, such as engines and electronics.

Paes explained the various pathways by which weapons have reached the Houthis. The major maritime route involves the use of traditional cargo vessels called dhows. Typically, the dhows depart from Iranian ports and sail towards the coast of Somalia, where the crews transfer the weapons onto smaller vessels. From there, they travel north, offloading their cargo on a secluded beach on the South coast of Yemen. Once on land, the cargo is then smuggled by criminal groups across the desert into Houthi controlled areas.

But this is not the only route. Some goods also reach the Houthis overland via Oman, entering Yemen through one of two official border crossings. In these cases, the weapons have been concealed under commercial cargo to escape the scrutiny of border guards.

Paes said that, because both the maritime and land pathways cross through areas nominally under the control of the internationally recognized Yemeni government, greater international support for Yemeni security forces could result in the interception of more shipments before they reach the Houthis’ hands. Improvements to national and multilateral export control regimes for dual-use goods that can be used in missiles and drones (often electronic components of Western origin), could also serve as a filter restricting the Houthis’ supplies—and would also be applicable to U.S. and European efforts to prevent those same goods reaching Iran and Russia.

With respect to Red Sea shipping, Paes explained that there was precedent for the Houthi missile and UAV attacks that have been going on since last fall. In fact, the group had carried out dozens of attacks against vessels going back to 2017. But he said the sheer number—almost 100 since November—was remarkable.

In Paes’s assessment, although the U.S.-led coalition’s strikes since January have degraded the Houthis’ capabilities, ending the present threat to global maritime commerce will ultimately require a political solution. But better application of naval anti-smuggling operations, local capacity-building, and strengthened export control systems can hinder the emergence of similar threats over the long run.

Expert Bio

Wolf-Christian Paes is a Senior Fellow for Armed Conflict at the International Institute for Strategic Studies (IISS). From 2018 until 2023, he served as the arms expert on the U.N. Panel of Experts on Yemen, where he monitored the sanctions regime imposed by the U.N. Security Council and reported on maritime security. Prior to that, he was the Head of Advisory Services at the Bonn International Center for Conflict Studies (BICC).

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