Situation Briefing. Updated September 13, 2026.
The short version
Houthi forces took Perim Island on September 11, completing control of the Bab el-Mandeb strait after seizing Mocha and Dhubab in the preceding 48 hours.
Transits fell from roughly 30 a day at the start of that week to 12 by Thursday, before the island changed hands.
This is not a blockade. Navigation was declared open to everyone except Saudi vessels, which is targeted economic warfare and far harder to build a coalition against.
The timing is the story. Saudi Arabia shut its Red Sea pipeline the same week, leaving its two principal export corridors impaired at once.
The strategic lesson: Bab el-Mandeb was the escape route from Hormuz. A backup that fails under the same conditions as the primary is not redundancy.
What happened
The Bab el-Mandeb is a strait roughly 30 kilometres wide at its narrowest, separating Yemen from Djibouti and Eritrea. It is the southern gate of the Red Sea, and therefore the southern gate of the Suez Canal. Around 10 to 15 percent of global maritime trade passes through it, including a significant share of Europe's oil and gas imports, and the wider corridor has historically carried up to a third of East-West container flows.
Sitting in the middle of it is Perim, also called Mayyun, a barren volcanic island with an airbase and little else. It divides the narrowest part of the strait into two navigable lanes. Whoever holds it holds the passage.
On September 10, Houthi forces took the port city of Mocha. The following day they took the coastal town of Dhubab, facing the island, and Yemeni government forces withdrew from Perim itself. Fighters crossed by boat and completed the takeover, part of a coastal offensive that also captured the Hanish islands.
Commercial traffic read the signal before the island fell. Transits ran at roughly 29 to 30 a day at the start of that week and dropped to 12 by Thursday as the advance began. Carriers started rerouting to the Cape of Good Hope before anyone had planted a flag.
Traffic fell by more than half before Perim changed hands. Sources: Lloyd's List Intelligence, AIS transit data.
The exemption is the strategy
Houthi military spokesman Yahya Saree announced that navigation through the strait was safe for all companies except Saudi vessels, which were already barred.
That single carve-out is the most sophisticated thing in this entire episode, and it deserves more attention than the territorial gain.
An indiscriminate blockade unifies the world against you. The 2023 and 2024 attack campaign hit vessels regardless of flag, and the response was a US-led naval coalition, an EU mission, and a broad consensus that the group had to be contained. Everyone was a victim, so everyone was an opponent.
A Saudi-only restriction does the opposite. It inflicts serious harm on one adversary while giving every other shipping nation a reason to stay out of it. A container line moving Asian goods to Europe has no direct grievance. China, which maintains a military base in Djibouti and depends heavily on this corridor, has no cargo being seized. The legal case for intervention weakens, the coalition-building case weakens, and the cost of the operation stays low.
Whether the guarantee holds is a separate question, and shipping insurers are pricing it as unreliable regardless. But as a piece of coercive design, it is the difference between a siege and a sanction.
Why the bypass was not a bypass
This is the part that matters most, and it connects directly to the Hormuz crisis.
When Iran effectively closed the Strait of Hormuz in February, Saudi Arabia's answer was the East-West pipeline, which carries crude 750 miles from Abqaiq on the Gulf coast to Yanbu on the Red Sea. It reached its full 7 million barrel per day capacity by late March. Tankers collected at Yanbu, and the kingdom kept exporting while the Gulf was shut.
But a cargo loaded at Yanbu still has to leave the Red Sea. It goes north through Suez, or south through the Bab el-Mandeb. There is no third door.
The pattern was already visible in the shipping data. By August, Lloyd's List Intelligence was recording very large crude carriers loading Yanbu crude and choosing the Suez Canal specifically to avoid the Bab el-Mandeb. The bypass route had already developed a preferred exit, which tells you the southern gate was considered risky months before it was taken.
Then the week of September 11 closed both doors at once. Saudi Arabia shut the East-West pipeline as a precaution after attacks on energy facilities at Abha, Najran and Jazan. Perim fell within 48 hours. The kingdom's Gulf corridor was already impaired, its Red Sea pipeline was offline, and the southern exit from the Red Sea was in hostile hands.
The structural point generalises well beyond Saudi Arabia. Redundancy is only redundancy if the backup fails independently of the primary. Two routes controlled by the same adversary coalition, threatened by the same weapons, in the same war, are not two routes. They are one route with two entrances. Every energy security plan built on the assumption that Hormuz and the Red Sea were separate hedges was, in engineering terms, a system with a common-mode failure nobody had modelled.
The cost of going around
When the Bab el-Mandeb is unusable, the only alternative is the Cape of Good Hope. That adds roughly 3,500 to 4,000 nautical miles to an Asia-Europe round trip, 10 to 14 days of transit, and around a million dollars in fuel per voyage, with fuel consumption rising 30 to 50 percent.
The Suez Canal absorbs the loss directly, and Egypt absorbs it after that. Canal revenue peaked near $9.6 billion in 2023 and fell to $3.6 billion the following year. The canal has been handling 14,000 to 15,000 vessels against roughly 26,000 before the crisis, and even August's recovery to a two-year high left traffic 41 percent below pre-crisis levels.
That recovery is now in question. Maersk had said more than 30 percent of Asia-Europe volumes previously routed around Africa had returned to Suez and that conditions for a full return were largely met. A hostile force holding the southern gate resets that calculation in a week.
The knock-on effects run further than freight rates. Asia-Europe container rates have been running 25 to 40 percent above baseline, Asia to US East Coast 15 to 25 percent higher. Cargo war-risk surcharges that peaked at $200 to $400 per TEU in early 2024 had settled to roughly $50 to $100; they will not stay there. And with naval assets concentrated on chokepoint security, Somali piracy has resurged in 2026 after years of dormancy, which is a second-order effect of the first-order response.
A chokepoint does not need to be closed to function as a weapon. It needs only to be credibly threatened. Twelve transits in a day where there were thirty tells you the market prices intent, not blockades, and intent is far cheaper to project than force.
Who wants what
The Houthis have converted a coastal offensive into permanent geographic leverage. Their cost structure is the core asymmetry: drones and anti-ship missiles are cheap, while naval interception and sustained deployment are extremely expensive. They also had domestic reasons for a war, and the offensive shattered a four-year informal ceasefire in Yemen's civil war.
Iran gains a second front without committing its own forces. Regional and Yemeni sources describe the coastal offensive as having come with guidance from the Revolutionary Guards. If Tehran's aim is leverage in negotiations over Hormuz, holding a second chokepoint through a proxy is the cheapest possible way to acquire it.
Saudi Arabia is the designated target and the most exposed party. It has responded with airstrikes in northern Yemen and by assembling a maritime coalition, and it is the one country explicitly barred from the strait.
Egypt has no military role and the largest economic stake after Saudi Arabia. Canal revenue is a primary source of hard currency, and the recovery it has been counting on runs through a gate it does not control.
The external powers converge on the Djibouti side. The United States, China, France, Japan and Italy all maintain military facilities there, and despite competing globally they share one interest: keeping the strait open. That layered deterrence is real, and it is also the wrong shape for this problem. It secures the African coast while the decisive terrain is the island and the Yemeni shore.
The EU runs Operation Aspides and has been weighing an expanded mandate, including minesweeping, with Kaja Kallas noting in July that if one vital trade route closes the other must clearly stay open. A Saudi-led maritime alliance was announced on July 30 with 43 of 51 invited countries signing, though notably neither the UAE nor Oman joined, which tells you something about how the Gulf states assess the risk of association.
Where it stands
Houthi forces hold Perim, Dhubab, Mocha and the Hanish islands. Yemeni government forces have announced plans to deploy heavy weapons and aircraft along the corridor to Mocha. Saudi Arabia has struck northern Yemen and warned Iran to restrain the group.
Dislodging an entrenched force from the island would, in the assessment of Yemeni officials, require a major international naval operation. No such operation exists. The coalitions that do exist were designed to escort ships past a threat, not to retake terrain.
The International Maritime Organization reaffirmed in July that international straits must remain open to peaceful navigation. That is the correct legal position and it has no enforcement mechanism attached.
What to watch
Whether the Saudi-only exemption holds. This is the single most important variable. If non-Saudi traffic genuinely passes unharmed, the strait functions as a sanctions instrument and global trade adapts around one victim. If a non-Saudi vessel is hit, the coalition calculus changes overnight and so does the insurance market.
Daily transit counts, not headlines. Thirty a day means the corridor works. Twelve means the market has priced the threat regardless of what anyone announces. That number is the honest indicator and it moves before the news does.
Whether the East-West pipeline restarts. Saudi Arabia cannot sustain a position where both corridors are impaired. The pipeline coming back online tells you the kingdom believes the Red Sea exit is viable; it staying shut tells you the opposite.
Egyptian hard currency. Canal revenue was projected at $5.8 to $6 billion by December. A sustained southern closure puts that forecast and Egypt's currency stability under pressure, which is how a Yemeni island becomes an IMF conversation.
Mandate changes at Aspides. An expansion into minesweeping or a redeployment of ships pledged to the Hormuz coalition would signal that Europe has concluded the southern gate matters more than the eastern one.
The deeper shift is already locked in. For two years the working assumption in shipping was that the Red Sea disruption was a phase, that attacks would ease, and that traffic would return to Suez. Carriers were rebuilding schedules on that assumption as recently as August. What changed this week is not the level of risk but its character: a threat that can be deterred has become terrain that has to be retaken, and nobody has volunteered to do it.
The Gate of Tears was never the hard part. Getting someone to reopen it is.
This Situation Briefing is updated monthly. Last revised September 13, 2026.