Shortly after the outbreak of the 2023 Israel-Hamas War, the Houthi movement in Yemen offered their support to Hamas. Their support has primarily taken the form of disrupting commercial traffic through the Bab al-Mandab Strait and the Red Sea through hijacking interdictions, firing missiles, and launching aerial drones, but also targeting Israel with missiles. The Houthis are doing so by the direction of Iran.

Iran’s interest in Yemen as part of their A2/AD strategy dates to 2009 when Iran was trying to invest in the Yemeni port of Midi. The Houthi movement has been part of Iran’s Anti-Area/Access Denial (A2/AD) strategy since the Houthi’s occupation of Sana in 2014 and Iranian support has been critical for the group. Iran has given the Houthis anti-ship ballistic missiles, radar systems, mines, and suicide drone boats (Water-Borne Improvised Explosive Devices – WBIED). The Houthis are the only Iranian-backed group that has received anti-ship missiles and placed them on display. These weapons assisted the Houthis during the Yemen civil war, which is frozen but still ongoing.

The Houthi’s Container shipping giant, Maersk, is now diverting all of its container ships from the Red Sea/Suez Canal route for the foreseeable future and now are to sail around South Africa’s Cape of Good Hope. This follows the pause that Maersk announced on 19 December that its ships would avoid the Red Sea region. Maersk is the first to announce that for the foreseeable future it would avoid the Suez Canal due to the insecurity that the Houthis have created.

Mohammed Ali al-Houthi, head of Yemen’s Houthi supreme revolutionary committee, stated the US-led coalition, Operation Prosperity Guardian, will be targeted. The Houthi rebels have experience with targeting vessels in the Red Sea, as Saudi Arabian and UAE ships were targeted when they were taking an active role during the Yemen Civil War. Anti-ship missiles, drones, and WBIEDs were used.

US intelligence believes that the Iranians are providing actionable intelligence to the Houthis for their recent blockade of the Red Sea. Iran recently deployed an Alborz destroyer to the Red Sea after the US sunk Houthi boats that were attempting to hijack a vessel.

The latest development may not change the outcome of the Houthi’s blockade of the Red Sea and the Bab al-Mandab Strait, but will have an impact on how the US-led coalition operates and may cause more alarm for commercial shipping. On 4 January 2023, the Houthis launched a WBIED into the strait and it detonated in the Red Sea. It was the first launch of a Houthi WBIED since 2019. It is known that the WBIEDs are in the Houthi arsenal, and it was only a matter of time before they were deployed into this conflict.

The WBIEDs were utilized during the Saudi Arabian intervention in the Yemen Civil War. In fact, a Royal Saudi Navy Al Madinah-class Frigate was attacked by three Houthi WBIEDs on 30 January 2017.  It is reported that the frigate was 30 miles (48km) from the port of Hudaydah. It is believed that the WBIED originated from the port of Hudaydah as well as other missile attacks during the Yemeni conflict.

Notably, Houthi WBIED attacks occurred between 2017 and 2019. Houthi WBIEDs first appeared as remote-controlled 10-meter patrol boats with two outboard motors and were equipped with explosives and a P-15 warhead intended to puncture a ship’s hull. The boat was laden with cabling and other equipment of Iranian origin. Conflict Armament Research examined one of these WBIEDs and it was based on a patrol ship (one of 60) that the UAE donated to the Yemeni Navy. Obviously, this boat, and other patrol boats refurbished as WBIEDs, were captured from the Yemeni Navy. It is unclear how many the Houthis may have or if they have acquired other vessels that are capable of venturing out 80 km (50 miles) into the Red Sea. However, there have been three revealed designs of the Houthi WBIED – Tawfan-1, Tawfan-2, and Tawfan-3 and all seem to have varied from the original 10-meter al-Fattan boat drone. The specifications of the various variants are unknown, but the Tawfan-3 has a sleeker design and the height of the hull is lower which suggests that the Houthis are attempting to limit its radar signature.

The US has deployed helicopters to interdict Houthi boats filled with hijackers. Now, the US will have to remain vigilant against boat drones that will operate with less radio chatter and can strike at any time. There have been concerns within the Pentagon that the US is expending a $2 million missile as a countermeasure to a $2,000 drone and therefore the cost/benefit will weigh heavily on the Houthi/Iranian side. To effectively counter WBIEDs, the US coalition will have to utilize more resources in terms of aircraft to ensure the safety of commercial traffic.

Operation Prosperity Guardian has been criticized for not targeting Houthi missile launch sites, command structure, and so forth. But by doing so, the US-led coalition would put the uneasy frozen Yemeni civil war at risk of heating up again. In 2022, the Saudi-led coalition stated that ports under Houthi control should be considered as military targets. Ultimately, it was the 2018 Stockholm Agreement that prevented this. The Stockholm Agreement ensured that the ports remained operational to allow the safe import of humanitarian assistance.  It also explains why Saudi Arabia and the UAE have not joined in the coalition’s efforts as it would also escalate tensions further.

The suicide boat drone is just another weapon that the Houthis can employ, and it will affect how Prosperity Guardian and commercial traffic operate in the region. It may also discourage other commercial shipping businesses from operating in the region and therefore will have to make the costly decision to divert around Cape Good Hope, but also prove to Iran that their investment in the Houthi movement for its A2/AD strategy was a bountiful one.


Feature Photo: “USS Nitze traverses the Red Sea, 2 Sept 2022” – US DoD Imagery, 2024

By Stewart Webb

The editor of DefenceReport and Senior Analyst, Stewart Webb holds a MScEcon in Security Studies from Aberystwyth University and a BA in Political Science from Acadia University. A frequent guest on defence issues for CTV National News, and other Canadian media outlets, his specialities include commentary on terrorist/insurgent activity and Canadian defence issues. Stewart can be contacted at: [email protected]