The growing number of attacks by the Houthis against Saudi Arabia is fueled by the large stock of missiles and drones amassed by the group over recent years. Although the UN has imposed an arms embargo on the group since 2015, the embargo has been largely ineffective. And although the UN Security Council has called it a terrorist group since 2022 and many countries have also designated it as such, the Houthi militia still enjoys support from a handful of states, chiefly Iran, and smuggling networks that maintain a steady flow of weapons to the outlaw group.
The London-based Conflict Armament Research has done extensive work over the years to track how the Houthis source and assemble advanced weaponry through international smuggling networks, tracing components from Iran and, more recently, direct or indirect supplies originating from manufacturers in other countries.
UNSC Resolution 2216 of April 14, 2015, imposed the embargo under Chapter VII of the UN Charter, meaning force could be used to enforce it. However, the UN stopped the Yemeni government from enforcing the embargo. Instead, it established weak mechanisms that were easily circumvented by the Houthis, allowing massive shipments of weapons to slip into Yemen without much difficulty.
Resolution 2216 stipulated that “all member states shall immediately take the necessary measures to prevent the direct or indirect supply, sale or transfer to, or for the benefit,” of the Houthis, “whether or not originating in their territories.” Included in the embargo were weapons and ammunition, military vehicles and equipment, paramilitary equipment, spare parts and technical assistance, training, financial or other assistance related to military activities.
UN embargoes were easily circumvented by the Houthis, allowing massive shipments to slip into Yemen
Dr. Abdel Aziz Aluwaisheg
To enforce the embargo, Resolution 2216 called on member states, “in particular states neighboring Yemen,” to inspect all cargo to Yemen in their territory “for the purpose of ensuring strict implementation” of the embargo. It further required all member states to “seize and dispose (such as through destruction, rendering inoperable, storage or transferring to a state other than the originating or destination states for disposal)” of any items discovered in violation of the embargo.
On paper, the embargo was tight, but when the government and its allies, the Coalition to Restore Legitimacy in Yemen, began to enforce the embargo by stopping and inspecting shipments going to Houthi-controlled ports, the UN came under tremendous pressure from some of its most powerful members to stop the enforcement. Instead, in May 2015, less than a month after the embargo was established, it established the UN Verification and Inspection Mechanism for Yemen to monitor commercial shipping and aid destined for Yemeni Red Sea ports not under the control of the Yemeni government.
However, from the start, this mechanism faced severe limitations that hindered its ability to stop weapons smuggling and fulfill its mandate. First among those obstacles was that the Houthis denied its officials access to the ports they controlled, preventing them from inspecting shipments. It had to rely on inspections at sea or in neighboring Djibouti. But it lacked interdiction authority and possessed no legal authority or operational capacity to intercept or board vessels at sea, relying instead on voluntary ship submissions for inspection. Obviously, ships carrying arms to the Houthis chose not to make those submissions.
In addition to importing whole weapons systems, the Houthis imported parts and reassembled them in Yemen
Dr. Abdel Aziz Aluwaisheg
The UN Verification and Inspection Mechanism for Yemen also faced funding shortages, which forced it to limit inspections to large boats with more than 100 tonnes of cargo. Clearly, you can pack a lot of missiles, drones and spare parts into a 99-tonne ship.
These limitations meant that most shipments went uninspected, bypassing the mechanism entirely to deliver their cargo directly to Houthi-controlled ports on the Red Sea.
There was a similar failure with the UN Mission to Support the Hodeidah Agreement. To stop the continued flow of arms through Houthi-controlled ports, the Yemeni government and the coalition sought to retake the port of Hodeidah. As their forces closed in on the port, the UN again came under great pressure to stop the fighting, preventing the government from taking control of the port. Instead, the UN brokered the Stockholm Agreement, which was seen as favoring the Houthis. UNSC Resolution 2452 endorsed the accord and the UN Mission to Support the Hodeidah Agreement was established in January 2019 to monitor compliance. Part of its mandate was to ensure that the port was used only for civilian purposes.
Repeating the earlier example, the Houthis denied the mission’s officials access, occupied its offices and housing facilities, brought in military reinforcements to the port in violation of the Stockholm Agreement, and used Hodeidah port to bring in weapons and to finance their operations.
After just one year of operation, the mission failed to effectively convene the Redeployment Coordination Committee, which was supposed to help enforce the agreement, leaving the 2018 Stockholm Agreement’s core goals frozen. There was also mistrust, with the Yemeni government repeatedly criticizing the UN Mission to Support the Hodeidah Agreement for acting as a “political shield” or cover for Houthi violations of the agreement through the continued importation of war materiel via the port.
After seven years of ineffective operation, the UN pulled the plug on the Hodeidah mission in March 2026, just as the US war with Iran started and the need for monitoring arms smuggling was greater than ever.
In addition to shipping contraband arms to Houthi-controlled ports, there was similar smuggling by land and through the government-controlled coast on the Red Sea, Gulf of Aden and Arabian Sea. According to various UN Panel of Experts reports, the Houthis have extensively used land and sea smuggling networks to keep a steady flow of weapons, components and dual-use technology.
Despite Iran’s denials, UN experts and the many interdictions of those weapons have repeatedly found that the Islamic Revolutionary Guard Corps and its affiliated networks have continued to supply the Houthis, by sea, land and air, with ballistic missiles, drones and naval components, and other weapons systems. Reports highlight inconsistent implementation, monitoring and enforcement of the sanctions and asset freezes by UN member states.
In addition to importing whole weapons systems, the Houthis imported parts of missiles and drones and reassembled them in Yemen. Thus, they were able to more effectively evade detection, cut costs and develop their own internal capacity to keep a steady supply of missiles and drones. For example, according to Conflict Armament Research, the Houthis were recently able to assemble a local version of Iran’s Kheibar Shekan precision-guided ballistic missile, which has a potential range of about 2,000km. This way, instead of smuggling complete missile systems, which are difficult to hide and move intact, smugglers break supply chains down into individual electronic and mechanical parts that are then assembled inside Yemen.
Earlier Conflict Armament Research investigations documented a well-established Iranian “weapon pipeline,” including antitank weapons, gyroscopes and components for suicide drones, such as the Qasef-1, matching Iranian national stockpiles.
A key to stopping the Houthi aggression is to stop the steady flow of weapons. As the UN mechanisms to stem that tide have failed one after the other, there is a need for a new regime. There are multiple naval outfits in the region — American, European and international — which should be empowered to do that job. The Saudi-led Multinational Maritime Defense Alliance, established in the summer, should be able to coordinate those efforts and add value to them.
Dr. Abdel Aziz Aluwaisheg is the GCC assistant secretary-general for political affairs and negotiation. The views expressed here are personal and do not necessarily represent those of the GCC.
X: @abuhamad1