Houthi Antishipping Attacks in the Bab al-Mandab Strait

On October 1, an antishipping missile launched from the Yemeni coast severely damaged the Swift, a former U.S. Navy High Speed Vessel-2 sold to the United Arab Emirates in 2015 and now operated by its National Marine Dredging Company as a troop landing and logistics ship. The incident -- the latest in a series of attacks by Iranian-backed Houthi rebels against shipping in the Bab al-Mandab Strait, the strategic chokepoint connecting the Suez Canal and Red Sea with the Indian Ocean -- triggered the deployment of a trio of U.S. Navy warships to the area, but other measures may be needed to fully curb the threat.

ANATOMY OF THE ATTACK

Ansar Allah, the militant arm of Yemen's Houthi movement, claimed to launch several rockets at the Swift, releasing video of the attack through their al-Masirah television channel as proof. The footage begins by showing the Swift filmed from another vessel during daylight hours, followed by close-range nighttime footage of a massive explosion and subsequent fire, suggesting the vessel was shadowed for some time by a Houthi dhow or speedboat that may have provided targeting data. As with previous Houthi missile strikes, the attackers presumably struck at night in order to avoid detection.

Anonymous U.S. officials told Fox News on October 3 that the Swift was engaged at close range with four Iranian-supplied shoulder-fired rockets, but this is inconsistent with the verified al-Masirah footage and the vessel's distance from shore. According to a Jane's Country Risk Report, the ship stopped transmitting its automatic identification signal a few seconds past midnight approximately 15.5 miles off the coast of Mokha, 38 miles north of the Bab al-Mandab. Shoulder-fired rockets lack the range achieved in this attack, and unguided longer-range rockets probably lack the accuracy.

A radar-guided antishipping missile attack is much more likely. Indeed, there are similarities between this incident and Hezbollah's July 2006 missile attack on the Israeli SAAR-5 missile corvette INS Hanit. In that attack, the Lebanese group seems to have used an Iranian-supplied C-802 antishipping cruise missile (either the Chinese CSS-N-8 Saccade or a reverse-engineered Iranian clone, the Noor).

Tellingly, al-Masirah's footage of the Swift attack shows a booster motor dropping away from the missile after launch, consistent with the C-802. Similar images were seen in October 2015, when the Houthis claimed antishipping missile attacks on Emirati and Saudi vessels. This suggests that Iran's Islamic Revolutionary Guard Corps may have supplied the rebels and their allies, the Yemeni Strategic Reserve Forces Missile Defense Command, with advanced antishipping missiles, just as Tehran supplied Hezbollah a decade earlier.

IMPACT ON UAE OPERATIONS

The Swift was designed as a high-speed logistics vessel, and its lightweight aluminum hull would deform and burn easily under the heat and impact created by a large antiship missile warhead such as that carried on the C-802. As seen in previous disasters, the widespread use of aluminum in hulls and superstructures can greatly hamper damage control efforts. Imagery shows very extensive damage to the Swift, which may be a constructive total loss. Casualties are likely high among the crew, which probably numbered between seventeen and thirty-five mostly non-Emirati contractors; UAE officials have noted that the ship was also ferrying wounded Yemenis. The damaged vessel was towed to the major new UAE naval base at Assab, Eritrea, located twenty-five miles away.

Since summer 2015, the Swift has logistically supported UAE operations in Yemen, shuttling continuously between Assab, Aden, and al-Mukalla. Losing the ship leaves a critical gap in the UAE's support capability, one that cannot be completely backfilled by the country's two eighty-meter landing ships and other smaller landing craft. The UAE will likely press into service additional chartered commercial roll-on/roll-off vehicle transports similar to those already transiting between Assab, Aden, al-Mukalla, and the UAE naval base at Fujairah on the Gulf of Oman. In the longer term, it may fast-track a contract for the delivery of new High Speed Support Vessel from Australian ship builder Austal, which provides catamarans developed from a platform similar to the Swift.

For their part, the Houthis may make further attempts to contest the Gulf coalition's freedom of operations in the Red Sea and Bab al-Mandab. The Swift attack was at least their fourth claimed missile strike on a coalition vessel since hostilities began. Last year, they claimed the October 7 and October 10 strikes on a UAE Navy Baynunah-class corvette and the KSAS Yunbou, a Royal Saudi Navy Durance-class replenishment ship. Like those vessels, the Swift was not equipped with close-in missile defense systems capable of intercepting an antiship missile, and other UAE supply ships and chartered commercial vessels may be similarly vulnerable.

Attacks may also extend to shore locations used by the coalition. On September 19, UAE vessels docked at Assab port were reportedly hit by mortar fire launched from a small boat. In addition, the Houthis or other actors apparently launched an amphibious raid on the UAE's air field in Assab the same night.

IMPLICATIONS FOR U.S. POLICY                                   

The Bab al-Mandab Strait is essential to the global economy. Over 4.7 million barrels of oil transited the busy waterway each day in 2015, and it is a critical path to the Persian Gulf for commercial shipping as well as the U.S. Navy. Ensuring access to the global commons has long been one of the Navy's missions, as reasserted by Chief of Naval Operations Adm. John Richardson in his January report "A Design for Maintaining Maritime Superiority." The Swift attack and the ten others claimed by the Houthis threaten this vital strait, and their C-802 missiles can reach across the entire width of the Red Sea as well.

The United States has a strong interest in pushing back on what may be an Iranian effort to drive the UAE and other Gulf coalition partners away from the Yemeni littoral. Tehran may also be hoping to widen the war to international shipping lanes and foreign territories such as Eritrea. Removing the coalition's ability to maneuver along the Yemeni coast and supply troops by sea could badly disrupt the war effort. Such a sea denial campaign could also reopen Iranian resupply routes to the Houthis and lengthen their war against Yemen's UN-recognized government. At a time when Iranian naval provocations in the Strait of Hormuz are becoming far more regular -- approximately twice as frequent as last year -- Washington can signal its support for safe freedom of navigation through a robust program of patrols in the Bab al-Mandab and Red Sea.

Toward this end, the Navy deployed three ships to the hot spot earlier this week: the destroyers USS Mason and USS Nitze and the amphibious transport ship USS Ponce. Guided missile destroyers of this type are well fortified against antiship attacks, armed with the Phalanx close-in weapons system, the AN/SLQ-32(V3) electronic warfare suite for active jamming, and Standard missiles for longer-range interception of inbound missiles. For as long as the deployment is maintained, these ships will be able to monitor threats, protect shipping, and respond to attacks as needed. If more antishipping strikes are launched, the Navy will likely begin escorting vessels through the area in a manner similar to Operation Active Endeavor, the NATO escort campaign that has improved security against terrorism and reduced maritime insurance rates in the Strait of Gibraltar since 9/11.

Washington and its international partners should also consider assisting Yemen's UN-backed government in gaining full control over the country's entire Red Sea coastline, perhaps by providing intelligence and seaborne support and helping the UAE replace the Swift (the Emiratis originally bought the ship from an Australian dredging company because a U.S. vessel could not be loaned to them). Half of that coast is already under coalition control, and completing the task would remove the Houthi antishipping threat more readily than a purely defensive approach.

Alexandre Mello is the lead security analyst at the energy advisory service Horizon Client Access. Cmdr. Jeremy Vaughan, U.S. Navy, is a Federal Executive Fellow at The Washington Institute who has completed multiple deployments to the Gulf. Michael Knights is a Lafer Fellow with the Institute. The views expressed herein are those of the authors and do not reflect the official policy or position of the U.S. Navy, U.S. Department of Defense, or U.S. government.