Curbing Houthi Attacks on Civilian Ships in the Bab al-Mandab

On July 25, Houthi rebels attacked a civilian oil tanker in the Red Sea west of Yemen’s Hodeida port. The vessel—a Saudi-flagged, double-hulled very large crude carrier (VLCC) named Arsan—had left Ras Tanura terminal on July 16 carrying about two million barrels of oil for Egypt. Since the attack, Saudi Arabia has suspended its movement of oil tankers through the Bab al-Mandab Strait, and such disruptions of global energy flows will continue until Houthi forces leave the coastal province of Hodeida.

ATTACK DETAILS AND RESPONSE

The Arsan was struck at the stern above the waterline, with imagery analysis showing an impact hole two to three meters wide and minor scorching damage on the outer hull. The most likely cause was a large unguided rocket fired from a fast-attack craft following behind the tanker. Less likely, it could have been a sea-skimming antiship missile such as Yemen’s C-801 or Iranian-origin C-802, or perhaps a large, explosive-laden aerial drone. The warhead may have detonated inside the vessel’s large aft ballast tank, with some signs of smoke damage around a door on the deck above. Afterward, the ship was escorted under its own power at reduced speed to the Saudi port of Jizan, accompanied by the Saudi frigate HMS Al-Dammam, which (contrary to some reports) was not damaged in the attack.

In response, Saudi energy minister Khalid al-Falih announced that “Saudi Arabia is temporarily halting all oil shipments through the Bab al-Mandab Strait...until the situation becomes clearer and maritime transit through Bab al-Mandab is safe.” In theory, Riyadh could use the Petroline pipeline (which has a capacity of 5 million barrels per day) to bypass the strait and deliver the affected 500,000-700,000 bpd of crude further north to Red Sea export terminals at Yanbu. Yet the fact remains that attacks by Iranian-backed Houthi militants continue to disrupt traffic in the world’s third-most important shipping strait after Hormuz and Malacca, at a time when Tehran has warned that any U.S. sanctions on its oil exports will push it to cut off all oil exports from the Persian Gulf.

Iranian political officials have yet to react to the Arsan attack, but Gen. Qasem Soleimani, head of the Islamic Revolutionary Guard Corps-Qods Force, blamed Saudi Arabia for the current “unsafe” situation in the Red Sea. For their part, the Houthis acknowledged responsibility for the Arsan attack, and also falsely claimed that they struck the Saudi frigate Al-Dammam and the main airport in the capital of the United Arab Emirates.

A PATTERN OF ATTACKING CIVILIAN VESSELS

In addition to strikes targeting U.S., Saudi, and Emirati warships in 2016-2017, the Arsan incident is one of several threats and attacks that the Houthis have directed at civilian shipping near the Bab al-Mandab:

• Drone boat attack on oil terminal, June 16, 2017. A self-guiding Shark-33 explosive drone boat, which can be programmed to home in on a target using electro-optical television systems, was used in an unsuccessful attack on a Saudi offshore loading facility in Jizan.
• Threat to shipping, November 12, 2017. The Houthi propaganda channel Al Masirah declared that “the battleships and oil tankers of the aggressors and their movements will not be safe from the fire of Yemeni naval forces if they are directed by the senior leadership [to attack].”
• Rocket attack on tanker, April 3, 2018. Houthi fast-attack craft fired on the Saudi double-hulled VLCC Abqaiq off the coast of Hodeida, using either rocket-propelled grenades or tactical rockets.
• Rocket attack on bulk food vessel, May 10, 2018. The Turkish-flagged bulk carrier Ince Inebolu was struck by a rocket in what the European counterpiracy mission EU NAVFOR characterized as “non-state Yemen-based actors firing a land-based missile or rocket at the vessel.”
• Indiscriminate naval mining since 2015. At various points, the Houthis have released drifting mines into the Bab al-Mandab, from which they have floated as far as ninety kilometers southwest of Aden after passing through the strait. According to the latest annual UN Panel of Experts report on Yemen, issued January 26, 2018, forty-four naval mines were found in the Red Sea and Gulf of Aden in 2017, of which four detonated on commercial vessels.
• Military use of radar on docked civilian vessels. The Houthis are repeatedly violating the law of armed conflict by forcing commercial ship operators in the Hodeida and Salif anchorage areas to let them use onboard maritime radars to surveil the Red Sea and generate targeting data. This measure seemed to begin after the Obama administration ordered strikes that destroyed Houthi coastal radar systems in October 2016.

SECURING THE RED SEA COAST

Houthi forces will be able to threaten international shipping for as long as they control any part of Yemen’s Red Sea shoreline. In June, major military advances by the internationally recognized Yemeni government and its Gulf coalition allies liberated 100 kilometers of coastline, but another 200 kilometers remain under Houthi control between Hodeida and Midi. Even if the Houthis agree to hand Hodeida’s port or main city area over to the government in a UN-brokered deal, they would still have the ability to strike international shipping and import Iranian weapons through beach landing points and the major port of Salif. Likewise, if they retain control over inland parts of Hodeida province, they could still launch guided drones against shipping.

These threats underline the need to distance Houthi forces from all areas of the Red Sea coast in order to make the Bab al-Mandab and its vital approaches safe for maritime traffic. Yemen’s UAE-backed coastal campaign is now readying for a new phase of offensive operations, positioning units less than 10 kilometers south of Hodeida city and reinforcing them strongly. The UAE military also enjoys complete freedom of maneuver along the coastline north of Hodeida, where strong Emirati amphibious forces have been reserved for use in future offensives.

The only factor holding back a full-scale effort to liberate the Red Sea coast is Riyadh and Abu Dhabi’s apparent unwillingness to fully support international peace talks with the Houthis. Thus far, UN special envoy Martin Griffiths has issued a proposal for Houthi forces to withdraw from Hodeida port and city, transfer port and customs operations to the Yemeni government, and allow onshore UN inspections of shipping to ensure the arms embargo on the rebels is not being violated. Patience is growing short within the Yemeni government and its coalition partners, who accuse the Houthis of stalling for time in order to reinforce and fortify Hodeida.

IMPLICATIONS FOR U.S. POLICY

The United States has a longstanding commitment to ensuring the security of international sea lanes, and the Bab al-Mandab Strait handles more than four million barrels of oil every day. Accordingly, Washington should back up its commitment by taking the following steps to secure the vital waterway:

• Warn the Houthis against further antishipping attacks, as well as drone and missile attacks on Saudi west coast energy installations.
• Prepare to strike if attacks continue, since U.S. warnings tend to have little impact on the Houthis unless backed by force. Any strikes should target Houthi antishipping and drone capabilities along the Red Sea coast, as when the Obama administration struck radar installations there in 2016.
• Direct more intelligence gathering against the Iranian “mothership” Saviz, a cargo vessel moored off the Red Sea archipelago of Dahlak. The Iranian military is likely using the Saviz to provide targeting data for Houthi antishipping attacks. Closer observation of the vessel and the threat of exposing its suspected intelligence role might be enough to make it leave the area. Alternatively, if authorities are able to prove its complicity in military activities, they may have a case for boarding and seizing it, which could yield further evidence that Iran is violating UN sanctions and supporting attacks on civilian vessels.
• Speed up the UN negotiations. The UN process of convincing the Houthis to withdraw from the Red Sea coast should not be hindered by open-ended stalling. If the Houthis do not agree to the proposal within a specified period of time, the United States should signal the Gulf coalition partners that they have fulfilled their commitment to seek a peaceful solution to the antishipping threat, and that they can take more forceful actions as needed.

Michael Knights, a senior fellow with The Washington Institute, has visited Yemen and the Gulf three times this year to study Houthi coastal defense tactics and weaponry. Farzin Nadimi is an associate fellow of the Institute, specializing in the security and defense affairs of Iran and the Gulf region.