Summary

The Houthis are expanding their influence across the Gulf of Aden and the Red Sea, building relationships with armed groups, marginalised communities and smuggling networks in the Horn of Africa. Drawing on around 100 interviews, documentary and interdiction records, satellite imagery, vessel tracking, telephone data and other sources, the research traces activity in Somalia, Djibouti, Sudan and Eritrea. It finds that initiatives which began as opportunistic efforts to circumvent arms embargoes and counter-smuggling operations are evolving into a more strategic project, although success is not guaranteed. The Houthis are seeking to become a new hub in the wider Axis of Resistance ecosystem by cultivating partners and sharing training, technology and supply networks. These developments could make Houthi supply chains more resilient, strengthen armed groups and further connect conflicts across an already volatile region.

Key Findings

• The Houthis have consolidated control over much of Yemen’s illicit economy, using established trade and smuggling networks to develop regional supply routes, recruitment channels and relationships across the Gulf of Aden and the Red Sea.
• What began as a scattered collection of opportunistic initiatives appears to be evolving into something more strategic and intentional, managed by senior operatives in Sana’a and drawing heavily on the earlier IRGC and Hezbollah playbook. Its success is by no means guaranteed.
• The relationship between the Houthis and al-Shabaab has been sustained and has yielded some results, including reported training in small arms, improvised explosive device manufacture and basic drone use. However, there is limited tangible evidence that advanced military capabilities have been transferred.
• Houthi involvement in Sudan currently appears mainly logistical and transactional. A growing, though not definitive, body of evidence indicates that people and arms are moving between Yemen and Sudan, while claims that Houthi personnel are supporting drone training and manufacture remain unverified.
• Many relationships cultivated by the Houthis remain thin and transactional, and some may fail. Yet even one or two groups acquiring the ability to manufacture and deploy advanced weapons could significantly alter conflict dynamics in Somalia, Sudan and the wider region.

Policy Implications

• The Houthi supply chain is diversifying and becoming more resilient. Expansion into Sudan, and potentially Eritrea, could create additional supply routes that are less vulnerable to interdiction efforts concentrated on the Gulf of Aden and Bab al-Mandab.
• The capability ladder can help policymakers distinguish between groups whose relationships with the Houthis remain at an early stage and those approaching independent weapons production. Available policy options differ sharply at each stage.
• Early-stage cultivation efforts should be monitored without relying on heavy-handed security responses that risk pushing marginalised communities towards the Houthis. Credible alternatives also need to address the grievances, weak governance and lack of other partners that make Houthi support attractive.
• Al-Shabaab’s use of Iranian-pattern explosive devices, anti-aircraft missiles or purpose-built attack drones would provide important evidence that its relationship with the Houthis had progressed from training towards active capability transfer.
• Responses need to account for the interconnected conflict ecosystem across the Red Sea and the Gulf of Aden. Narrow interventions focused on individual groups, countries or smuggling routes may overlook the relationships and supply networks that allow armed actors to adapt to disruption.

This report was first published on the The Century Foundation’s website.