Expanding Al Shabaab–Houthi Ties Escalate Security Threats to Red Sea Region

Growing collaboration between al Shabaab and the Houthis is enabling both militant groups and contributing to heightened maritime and land-based threats on both sides of the Gulf of Aden.

A ground-to-ground missile is displayed during a Houthi military parade in Sana’a, the capital of Yemen. (Photo: AFP/Mohammed Huwais)

Evidence of growing collaboration between al Shabaab in Somalia and Yemen’s Houthis is heightening risks to maritime traffic in the Red Sea, Gulf of Aden, and Western Indian Ocean while strengthening the disruptive capacity of both groups.

In a show of support for Hamas in its conflict with Israel, the Houthis have used drones, missiles, and small boats since November 2023 totarget over 100 commercial vessels(striking 48, including 6 that were incapacitated) attempting to traverse the 70-mile long and 20-mile wide (at its narrowest) Bab al Mandab Strait separating Africa from the Arabian Peninsula.

Piracy in the region has also spiked. There had been minimal piracy activity since 2015, andthe last hijacking was in 2019. Since November 2023, however, there have been47 piracy-related eventsin the Gulf of Aden and Western Indian Ocean.

The rise in insecurity has had direct economic impacts on the global economy. Shipping through the Suez Canal (which accounts for about12-15 percent of worldwide tradeand 30 percent of container ship traffic) hasdropped by 50-60 percent.

Re-routing of commercial vessels around the Cape of Good Hopein South Africa has increased by 420 percent. This hasadded up to 2 weeks and 6,000 nautical miles to their journeys. Thecost of shipping in 2024 jumped to almost $6,000 per containerfrom $1,660 in 2023, raising the costs for consumers. Egypt has seen its nearly $10 billion annual revenues from Suez Canal trafficcut by more than 70 percent, incurring a monthly loss of $800 million.

Al Shabaab gains improved materiel (weaponized drones, ballistic missiles) and training from this relationship. Al Shabaab is simultaneously able to further expand andentrench the criminal enterprisesthat fund its operations.

This cooperation is expanding the destabilizing capacities of these militant groups on both sides of the Bab al Mandab Strait.

The Houthis benefit from Al Shabaab’s support of disruptive piracy activity in the Gulf of Aden and Western Indian Ocean as well as from more diversified supply arteries. This strengthens the Houthis’ ability to threaten maritime traffic in the region while deepening their leverage vis-à-vis the United Nations-backed government in Yemen.

This cooperation is expanding the destabilizing capacities of these militant groups on both sides of the Bab al Mandab Strait while further complicating the challenges of monitoring 1,800 miles of vulnerable coastline along the Red Sea, Gulf of Aden, and Western Indian Ocean.

In February 2025, the United Nations (UN) reported evidence of not just communication between the Houthis and al Shabaab but physical meetings in 2024 concerning thetransference of materiel and training from the Houthis to al Shabaabin exchange for increased piracy and arms smuggling. Previously, most observers believed that the al Qaeda-affiliated al Shabaab was not cooperating with the Houthis, a group with a different ideology and agenda that benefits from the support and assistance of Iran.

The Houthis (also known as Ansarullah or Ansar Allah) are aZaydi Shiite movementthat has been fighting the internationally recognized Sunni-majority government in Yemen since 2004.Iran has been shipping weapons to the Houthissince April 2015. In 2017, the Houthis escalated the scope of their offensive by firing ballistic missiles at Saudi Arabia and, in 2022, at the United Arab Emirates (UAE), both of which are supporters of the Yemeni government.

Al Shabaab (also known as Harakat al Shabaab al Mujahideen) is a militant Sunni Islamist group that was founded in 2006 and has been the leading threat to the government of Somalia while aiming to create an Islamic state in ethnically Somali areas of Djibouti, Ethiopia, and Kenya. Al Shabaab is a part of the al Qaeda network and has targeted countries in the region supporting the African Union stabilization force in Somalia as well as the United States. Al Shabaab is one of thebest resourced militant Islamist groups in Africaand holds wide expanses of territory in Somalia.

So long as the Houthis and al Shabaab maintain their alliance, shipping through the Suez Canal will be persistently at risk.

Until recently, there has been little reason for the two parties to cooperate. In fact, al Shabaab’s affiliate in Yemen, al Qaeda in the Arabian Peninsula (AQAP), has in the past been thetarget of Houthi offensives. Nevertheless, since 2022AQAP and the Houthis have maintained a non-aggression pactthat has includedcooperation in security and intelligence, providing safe havens for each other, and coordinating efforts to target Yemeni government forces.

The start of the Israel–Hamas conflict in October 2023 provided the groups on both sides of the Strait an opportunity to leverage the pragmatic arrangement between the Houthis and the al Qaeda network to inject insecurity into a wider regional area of operations while advancing their respective interests.

The Gulf of Aden is virtually entirely encompassed by Somalia and Yemen’s shorelines. So long as the Houthis and al Shabaab maintain their alliance, and improve their capabilities in the process, shipping through the Suez Canal will be persistently at risk of attack, paying a “protection” tax, or ransom (due to piracy) to one or both groups.

As the Houthis have expanded their regional influence, they have beenwidening their network of international partnersto include Russia and the Islamic Resistance in Iraq. The former maintains military intelligence personnel in Houthi-held areas of Yemen and hasshared satellite intelligence datawith the group. This wider scope of activity relies onmaintaining a weapons supply chain and expanding funding sources to pay for it.

The Houthis have reportedly earned an estimated $180 million a month from fees paid by unnamed shipping agents.

As a result of their assault on vessels and the continued instability in the Red Sea region, the Houthis have reportedly earned an estimated $180 million a month from fees paid by unnamed shipping agents to secure safe passage through the region.

Cooperation with al Shabaab and AQAP has provided the Houthis with more access to the Arabian Sea and Western Indian Ocean. Al Shabaab’s network of fighters, sympathizers, and smugglers across Somalia and northern Kenya, moreover, offers the Houthis more opportunities to get arms shipments (many of which have come from Iran) out of the Indian Ocean and into coast-hugging skiffs or overland to the Gulf of Aden where they may have a better chance of reaching Yemeni shores.

In January 2024,a dhow was intercepted in Somali waters with ballistic and cruise missile components, guidance and warheads for medium-range ballistic missiles (MRBM), and anti-ship cruise missiles (ASCM) that were intended for Yemen. This was one of at least 10 interceptions of arms smuggling documented by the UN and others between October 2023 through 2024. In August 2024, Yemeni National Resistance Forces seized a vesselsmuggling hydrogen fuel cells, which experts believed would allow Houthi drones to carry larger payloads and to travel for far longer periods and ranges.

Illustrative Weapons Interdictions Between Somalia and Yemen since October 2023

Sources: United Nations,Africa Defense Forum, Conflict Armament Research, ACLED

Though it can build its own IEDs, steal weapons from the Somali National Army and African Union forces, and maintain an arms smuggling trade (such asrocket launchers, machine guns and sniper rifles), al Shabaabhas struggled to acquire higher-end weapons. By helping to keep the Houthi trade routes open and increase piracy off Somalia, al Shabaab has receivedadvanced weapons and trainingfrom the Houthis, including weaponized drones.

The UN found al Shabaab received technical instruction from the Houthis and shipments of weapons from Yemen between June and September of 2024. The weapons were used in al Shabaabattacks against African Union forcesin September and November. The UN further discovered that al Shabaab had sent over a dozen operatives to Yemen for training from AQAP including in unmanned aerial vehicle technology.

In August 2024, Puntland authorities arrested seven suspected al Shabaab members andseized five suicide drones. Al Shabaab had used drones for years to gather intelligence, perform reconnaissance, and to create propaganda films, but it had not yet used weaponized drones. Experts believe this is just the start ofmore advanced weapons that could come after trainingfrom the Houthis. Al Shabaab demonstrated greater capabilities and the deployment of drones in its 2025 offensive where it was able to retake considerable amounts of territory the government of Somalia had gained in previous years.

The Greek-flagged oil tanker ‘Sounion’ after being heavily damaged by Houthis in multiple attacks off Yemen in August 2024.(Photo: NurPhoto/Nicolas Koutsokostas)

Shipping industry experts have assessed that the re-routing of merchant ships south of the Cape of Good Hope has alsoincreased income opportunities for al Shabaab-sponsored pirates. Thehijacking of the MV Abdullah by Somali pirates600 nautical miles off of Mogadishu in April of 2024, for example, earned them $5 million. Taxes from piracy could expand al Shabaab’s estimated $200 million in annual revenues and help propel its territorial expansion.

Since the start of the Houthi attacks on the Red Sea, two regional defensive naval missions—the U.S.-led Operation Prosperity Guardian and the EU-led Operation Aspides—acted tointercept Houthi attacks, escort merchant vessels, and rescue and salvage stricken ships.

Starting in 2024,the United Kingdom and the United States mounted airstrikes on Houthi targetsto maintain maritime passage. This came on top of ongoing Saudi Arabian and UAE military support for the UN-recognized Yemeni government.

Smuggling routes appear to be most concentrated in the Puntland region of northern Somalia, from which weapons are transported to al Shabaab strongholds in central and southern regions of the country. To inhibit this route and the resurgence in Somali piracy, the Puntland Maritime Police Force and international navies (includingIndian, British, and U.S.) have disrupted a number of piracy incidents. Further, the European Union extended itsanti-piracy naval operation Atalanta, its maritime security capacity building mission (EUCAP Somalia), and its military training mission (EUTM Somalia).

The federal government of Somalia, along with thefederal member states, clan militias, and African Union forces, has sustained the multifront conflict with al Shabaab, engaging much of central and southern Somalia. This fighting has resulted in roughly 4,500 fatalities in 2024 alone.

The Houthi–al Shabaab alliance reflects the leveraging of a vital international chokehold bordering two of the poorest countries in the world.

In March 2025, the UNextended the longstanding sanctions regimeon al Shabaab and renewed the mandate of its Panel of Experts on Somalia to investigate further and report on al Shabaab’s finances and activities.

Despite these collective efforts, al Shabaab and the Houthis have proven to be resilient spoilers.

The Houthi–al Shabaab alliance reflects the leveraging of a vital international chokehold bordering two of the poorest countries in the world to elevate each militant group’s threat. An increase in their respective finances and technological know-how not only has the potential to impede any progress in stabilizing Somalia and Yemen but to further expand the reach of each nonstate actor in the region and beyond.

A persistently lawless, unstable Red Sea and Gulf of Aden, in turn, would be highly disruptive to international security and the global economy.

Given that both militant groups are well entrenched in their respective host countries, significantly degrading this threat will require more than maritime action. Sustained efforts to reduce each group’s territorial control will also be needed as these land bases have provided the platforms from which the nonstate actors have been able to launch attacks at sea, expand their revenue flows, and build their military capacity.

Based on reporting by ACSS