Excitement in the Bab-el-Mandeb

The last few days have seen a great deal of excitement in the area around the Bab-el-Mandeb,¹ the strait that separates Yemen from Somalia at the southern end of the Red Sea.

The Bab-el-Mandeb is a vital chokepoint for global sea commerce, sitting astride the path between the Indian Ocean and the Mediterranean via the Suez Canal. Something like 9% of the world's seaborne oil trade passes through, along with huge numbers of container ships and bulk carriers. And unfortunately for those who would very much like these vessels to pass unhindered, it happens to be adjacent to some of the most unstable countries on Earth. 15 years ago, the main threat in the region was piracy from Somalia, which was brought under control via a combination of naval patrols, better anti-pirate measures aboard merchant ships, and attempts to reduce the pirate population at the source. But as those efforts bore fruit a decade ago, civil war broke out in Yemen and the Houthis, who have been trying to overthrow the previous government and defeat its Saudi patrons, have occasionally lobbed missiles at passing ships. The most notable incident until recently took place in 2016, when catamaran HSV-2 Swift was attacked off the coast of Yemen, prompting the dispatch of destroyers Mason and Nitze.

In the next few days, Mason was the focus of three separate attacks, although frustratingly few details have been made public about the exact sequence of events. The first encounter, on October 9th, took place while Mason was escorting LPD Ponce, known for being the first ship to take an operational laser weapon to sea. A single cruise missile was fired and engaged with two SM-2s and an ESSM, as well as a Nulka decoy, but it is unclear if the missile was shot down, decoyed, or crashed on its own. A few hours later, a second missile was launched, but ran out of fuel short of the two ships. Three days later, two more missiles were fired, at least one of which is confirmed to have been shot down. The Navy responded with Tomahawk strikes to destroy three radar sites. There is some confusion over a third alleged attack on the 15th. The DoD was confused if anything actually happened, but reports are that at least five missiles were fired at Mason and Nitze, four of which were either decoyed off or shot down by Mason. The last got quite close to Nitze before a Nulka drew it off.

Nor were these the only attacks made by the Houthis on ships in the Red Sea. We have only limited details and I'm trying to get this out quickly but it appears that they have made numerous attempts to attack ships offshore using a combination of mines, suicide boats and missiles. Most of these were directed at Saudi and Emirati warships supporting the anti-Houthi intervention, and they appear to have trailed off after 2018 or so.

This all changed after the October 7th attack on Israel. The Saudi intervention has largely wound down, and the Houthis displayed a number of weapons last year, including several anti-ship ballistic missiles provided by Iran. Action in the Red Sea began on October 20th, when destroyer Carney downed 11 cruise missiles² launched by the Houthis at targets in Israel. The Houthis have continued to launch missiles at Israel, and so far as I am aware, American destroyers have shot them all down, with Carney continuing to contribute, alongside Thomas Hudner. Mason also reappeared on the scene, deploying with the Eisenhower Battle Group, and in late November, she responded to the boarding of the oil tanker MV Central Park, detaining five suspected Somali pirates. The Houthis were not particularly happy about this, and launched an anti-ship ballistic missile into the area. It missed both ships by a wide margin, leaving doubts as to whether it was even targeted at them.

The excitement ramped up a week ago, on December 3rd, with the most consequential engagement of the whole campaign so far. Carney was still in the southern Red Sea, and detected another ASBM that impacted near the bulk carrier Unity Explorer before shooting down what CENTCOM³ describes as a Houthi drone. The statement seems to indicate that they believe it was actually a missile, although it could just as easily have been a surveillance drone scouting for more effective missiles.⁴ Half an hour after the drone was downed, Carney picked up a distress call stating that Unity Explorer had been hit by a missile. A second drone was shot down while Carney was providing aid to Unity Explorer, and another ship, MV Number 9, was hit by a second missile three hours later. An hour after that, MV Sophie II put out a distress call, and Carney shot down a third drone while en route to provide aid. To cap off the recounting of events, Mason downed a drone on Wednesday.

There are several interesting aspects to the events of the 3rd. First, I suspect that all but the first missile were cruise missiles instead of ballistic. At least for the first and third missile hits, the CENTCOM statement gives no indication that Carney knew the missiles were inbound before they hit, which is unlikely for ballistic missiles with Aegis in the area, but pretty plausible for a low-flying cruise missile targeting a ship tens of miles away. Second, all three ships targeted were bulk carriers, which meant that damage was relatively minimal. If the ship is either a big empty metal box or a big metal box full of rocks, then a typical anti-ship missile designed to damage a frigate isn't going to do much more than annoy the insurers. The Houthis have claimed that they are only targeting ships linked to Israel, although there's some dispute as to how close the links of all the ships are. It's not clear if they just happened to hit three bulk carriers by chance (unlikely but not completely impossible, as bulk carriers make up 40+% of global merchant tonnage and at least a quarter of large merchant ships, and more in the Bab-el-Mandeb area based on a spot-check of AIS data), if the Israelis are deep into the bulk carrier business for some unfathomable reason, or if they were trying to send a message about their ability to interdict traffic through the Red Sea without really annoying someone or causing a major environmental disaster.

So what lessons can we draw from all of this? Well, first, the destroyers in the Red Sea are going through a lot of missiles, which suggests we may need to buy more. Second, Iranian ASBMs don't seem to work all that well, although their cruise missiles seem to perform fairly well. Third, this is a serious threat to global maritime commerce. Remember the chaos caused when the Suez Canal was blocked in early 2021? This would be almost precisely as bad as that was if the threat forced us to keep civilian ships out of the area. So far, there's no indication that the systems are a threat to ships with reasonable defenses, although anything without Aegis might be vulnerable to the ASBMs if the missiles actually work. And while it would certainly be possible to convoy ships through the Bab-el-Mandeb (the parallels to Operation Prime Chance are obvious) this would be a significant force commitment for an already-stretched USN, as well as slowing commerce through the area. And lastly, Aegis works, and the anti-ship missile threat is nowhere near as serious for warships as it is often portrayed to be.

2024 Postscript: Unfortunately, the Bab el Mandeb is still dangerous to transit thanks to the Houthis. For some reason, the Biden Adminsitration has not made it a priority to either interdict the supply of missiles to the Houthis or to aggressively go after their forces on land. We bomb things like radars after the Houthis do something specifically annoying, instead of taking them out preemptively, and have left enough targets that Israel has gotten into the game. We have gotten lots of evidence that Aegis works, and that we don't care enough to maintain free passage through such a vital shipping route.