The Houthis’ Asymmetrical Maritime Warfare

by April 2024
US destroyer shoots down Houthi missiles and drones. Photo credit: ABACA via Reuters Connect / Mass Communication Specialist 3rd Class Michael J. Lieberknecht.

The war launched by Hamas on October 7, 2023 caught Israel and its defense establishment by surprise, but the same cannot be said of the missile attacks on Red Sea shipping by the Houthi rebel regime in Yemen. 

Ever since the Houthis took control of Yemen’s capital San’a in 2014, Israeli analysts have warned that their missiles would be turned against Israel and its allies – in keeping with the slogan on the Houthis’ flag: ” Allahu Akbar, Death to America, Death to Israel, Curse be upon the Jews, Victory for Islam.”

As early as 2017, Egyptian observers of Yemen also warned that the missiles Iran was giving the Houthis would come to threaten traffic in the Suez Canal – as has indeed occurred, with severe consequences for the Egyptian economy. In short, the Houthi maritime campaign was no surprise.

Rise of the Houthis

The Houthi movement, named after the clan of their founder, arose in Yemen in the early 1990s. In 2004 the movement launched a rebellion against the central government, accusing it inter alia of being too close to the US (and Israel). By 2009, after several rounds of fighting, the Houthis controlled the country’s northwest, and by 2015 had taken over the capital of San’a, later adding the key port of Hudaydah and much of the Red Sea coastal plain. This led to the creation of an Arab coalition to defeat them, led by Saudi Arabia and the UAE. 

During the years of the civil war the Houthis began to target ships in the Red Sea. In the southern section of the Red Sea they used mines, explosive boats (one of which penetrated a neighboring Saudi port in 2017), shore-to-sea missiles, and drones. Towards the end of 2016 they launched missiles towards American naval ships in the Red Sea. The Obama Administration settled for a largely symbolic response, firing a few cruise missiles at radar sites in Houthi-controlled areas.

Iran supplies missiles used to strike targets inside Saudi Arabia and the UAE and, together with Lebanese Hizbullah, trains the Houthis and provides operational guidance. Since 2016 Iran has positioned a command and intelligence ship in the Red Sea under the commercial guise of the Islamic Republic of Iran Shipping Line Group. In April 2021, when this Iranian ship was damaged by a limpet mine (no country claimed responsibility) and towed back to Iran, it was replaced by the Beshahd. This spy ship left the Red Sea early in January 2024 and relocated to the Gulf of Aden, ahead of American strikes against Houthi targets which commenced on January 12. 

In addition, the Iranian navy sends occasional task forces – usually a frigate with one or two support ships – to establish a presence in the Gulf of Aden and the Red Sea. 

The Houthis act as Iran’s allies, but not always as obedient proxies. For instance, they struck a loose ceasefire agreement in April 2022, through UN mediation, with the opposing Arab coalition. Both the civil war years and the lull that followed after mid-2022 provided the Houthis with opportunities for improving their military capabilities, in terms of force build-up and combat readiness. 

In a massive parade in San’a in September 2023, the group displayed an array of advanced weapons, including ballistic and cruise missiles, UAVs and drones, explosive motorboats, and sea mines. Overall, the Houthi regime has mobilized a military force of 250,000 personnel. Its navy, lacking missile boats and large vessels, emulates the IRGC methods of asymmetrical warfare at sea. 

Ballistic missiles and armed drones displayed in a military parade in San’a, September 21, 2023. Video source: REUTERS / Abdulrahman Al-Ansi, Adel al-Khadher, Heba Fouad, Abir Al Ahmar.

Assessing the Damage Thus Far

After the Hamas offensive of October 7, 2023, the Houthis threatened to intervene unless Israel ended its operations in Gaza. These threats were followed on October 19 by drones, cruise missiles, and ballistic missiles launched against Israel’s Red Sea port of Eilat, Israel’s gateway to East Asia.

The government in San’a then added the threat that further fighting in Gaza would lead to attacks on Israeli shipping in the Red Sea. On November 19, a Houthi commando team landed by helicopter on what they presumably thought was an Israeli ship, the vehicle carrier Galaxy Leader (belonging, in fact, to a Japanese company partly owned by an Israeli). They hijacked it as it was sailing south, detained the crew, and forced the ship into Hudaydah harbor, where it was turned into a propaganda prop and a local tourist attraction. 

The Galaxy leader raid was the opening shot for the intense activities of the Houthis in the southern Red Sea and the Gulf of Aden against shipping targets allegedly associated with Israel or owned by Israelis (false claims in most cases) or on their way to or from Israel. Later, once the US and the UK began on January 12 to strike Houthi targets, ships associated with both countries were also marked for attack. 

On January 17, 2024 the US re-designated the Houthis a terrorist organization. By March, more than 70 Houthis attacks on commercial shipping and American and British navy vessels had been recorded.

Iran and Houthi related maritime incidents
Houthi maritime incidents as of March 15, 2024. List is not exhaustive and location is not necessarily authoritative. Information source: Damien Symon,

The Houthis deploy saturation tactics, launching a large number of drones simultaneously. Based on Iranian capabilities – apparently acquired from China and North Korea – the Houthis increasingly use a sophisticated anti-ship ballistic missile armed with an electro-optical sensor that can “open its eye” and aim, once it is within range of the target ship. They also used air defense missiles converted into “maritime ballistic missiles” – with limited effect to date.

In most cases, the damage has been limited. Ships like the Zografia (Maltese flag, Greek ownership) and the Genco Picardy (Marshall Islands flag, US ownership) both hit in mid-January, simply sailed on. But in several cases, the ships were abandoned: the tanker Ruby Mar (Belize flag, British ownership) was hit on February 28 was disabled, abandoned and ultimately sank. 

The economic impact has been limited. Shipping lines and owners of commercial vessels have decided to avoid passage through the Bab al-Mandeb Straits and instead sail around Africa. This adds 10 days (36 as compared to 26) to the voyage time from Singapore to Rotterdam. The main impact has been on the Suez Canal, and hence on the Egyptian economy. The impact on transport costs, and thus on global inflation, has not been significant. 

Several other navies of the free world, including French, German and Indian vessels, have joined in defensive missions; only the US and the UK have attacked Houthi targets with the aim of reducing their capabilities. By late March, the head of the US Central Command Air Force, Lt. General Alexus Grynkewich, assessed that the pace of Houthis attacks was slowing because their supplies of drone swarms and ASBMs were dwindling under persistent allied attacks on their bases.

Re-routing of commercial shipping caused by Houthi attacks. Effects on global inflation are minimal. Source: Reuters.

Continuing Attacks

Despite occasional captures by Western navies, Iranian weapons continue to reach Yemen on board dhows, traditional fishing vessels, which ply the waters of the Gulf of Oman and the Arabian Sea, and are then smuggled across Oman into Yemen. One such dhow was apprehended by the US Navy on January 11, 2024. Training in Iran is also ongoing, and in January 2024 British sources reported that 200 Houthi elite troops went through special maritime training at the Khamene’i Academy by the Caspian Sea. 

There are unverified, persistent reports about US efforts via Omani mediation to cut a deal with Iran to restrain the Houthis – or with the Houthis directly – offering to once again remove the Houthis from the US terrorist list, in return for an end to the campaign.

To date, the Houthi leadership not only remains committed to the present campaign but also threatens to expand the scope of their campaign to the Indian Ocean and even to ships taking the Cape of Good Hope route – bravado not necessarily supported by operational capabilities. 

Initial lessons indicate that while this asymmetrical warfare has had limited global impact, the US-led responses have proven ineffective. Furthermore it is not clear whether or not applying new pressure on the Houthis’ patron would be effective. Iran, even if it wished to do so (as it did vis-à-vis its proxies in Iraq) may not be able to put the Houthi djinns back in the bottle. 

Would a ceasefire in Gaza lead the Houthis to end their campaign? A temporary ceasefire certainly would not. Their sense of self-confidence must have been bolstered first by their ability to withstand the Arab coalition’s war against them, and then by their perception of success in the current maritime offensive. It is safe to assume that until their source of missiles and other war supplies dries up, the Houthis will continue their piracy.

Shlomo Gueta
Shlomo Gueta is a research fellow at the Institute for Maritime Policy and Strategy, part of the Haifa-based Israeli National Center of Blue Economy. A former captain in Israel’s navy, he served as the head of the research division of Naval Intelligence.
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