After Mocha: Why Bab al-Mandab Has Become the Strait to Watch

Who controls what in Yemen?

The Houthis control the northwestern regions of Yemen, including the capital, Sanaa, while forces affiliated with the internationally recognised government control most of the rest of the country.

Areas of control in Yemen and the strategic Bab al-Mandab corridor. Source: Al Jazeera graphic supplied for editorial reference, 9 September 2026. Graphic withheld from publication pending rights clearance.

AT A GLANCE: Mocha has fallen • Bab al-Mandab is under renewed pressure • Saudi export routes face a second maritime risk

The seizure of Mocha by Yemen’s Houthi movement has changed the geography of the war at the southern end of the Red Sea. What had looked only days earlier like a counter-offensive by forces aligned with Yemen’s internationally recognised government has become a rapid Houthi advance down the coastal plain, bringing the movement closer to Dhubab, Perim Island and the Bab al-Mandab Strait.

Mocha matters because the battle is no longer only about who controls another Yemeni port. The city sits roughly 60 kilometres from Bab al-Mandab, the narrow maritime gateway between the Red Sea and the Gulf of Aden. In ordinary circumstances the strait is already critical to trade between Europe and Asia. In 2026 it has become more important still because disruption at the Strait of Hormuz has pushed more Saudi and regional energy flows westward toward the Red Sea.

That shift is visible in US Energy Information Administration data. The EIA estimates that petroleum and other liquid flows through Bab al-Mandab averaged 8.1 million barrels a day in the second quarter of 2026, up from 5.4 million barrels a day in the final quarter of 2025. Over the same period, flows through Hormuz fell to 4.9 million barrels a day from 21.6 million. The effect has been to turn the Red Sea route from an alternative into a strategic pressure point of its own.

A battlefield reversal in five days

Control of Terrain in Southern Hudaydah and Taiz Governorates — As of September 5, 2026 at 2:00 PM ET

• The NRF and other ROYG-aligned forces launched a counteroffensive into southern Hudaydah Governorate. The counteroffensive temporarily opened a salient that threatened Houthi GLOCs between the Red Sea coast and the front line surrounding Taiz City
• ROYG-aligned forces advanced north from defensive positions that they had maintained along the front line for years into open flatland that is difficult to defend
• ROYG and Houthi forces have engaged in heavy combat in the vicinity of Maqbanah, Barah, and Kadha since the Houthis launched an offensive in the area on September 3
• Houthi Controlled Terrain
• Contested ROYG-Houthi Territory
• Claimed Extent of Houthi Offensive

5 September: ROYG-aligned forces push north from longstanding defensive positions. Source: Institute for the Study of War / Critical Threats Project (ISW-CTP), 5 September 2026. Map withheld from publication pending rights clearance.

Control of Terrain in Southern Hudaydah and Taiz Governorates — As of September 10, 2026 at 8:00 AM ET

• Houthi Controlled Terrain
• Contested ROYG-Houthi Territory
• Claimed Extent of Houthi Offensive

10 September: Houthi forces counterattack, advance across the coastal plain and take Mocha. Source: Institute for the Study of War / Critical Threats Project (ISW-CTP), 10 September 2026. Map withheld from publication pending rights clearance.

The contrast between the two ISW-CTP maps is stark. On 5 September, government-aligned forces were advancing north and threatening Houthi ground lines of communication between the Red Sea coast and the Taiz front. By 10 September, Houthi reinforcements had reversed that momentum. The movement pushed through Hays, expanded across the coastal plain and entered Mocha as opposing forces withdrew south.

Al Jazeera reported on 10 September that Houthi forces had seized the city while troops aligned with the internationally recognised government regrouped. Council member Tareq Saleh described the retreat as tactical. The next question is whether that withdrawal can be stabilised around Dhubab or whether the Houthis can continue south toward the narrowest and most strategically sensitive section of Yemen’s Red Sea coast.

The strategic danger is not that one side has already “closed” Bab al-Mandab. It is that the cost and risk of keeping the route open are rising at the same time that Hormuz remains constrained.

Mocha is a gateway, not the end state

Control of Mocha does not by itself amount to control of Bab al-Mandab. The strait remains an international waterway, and US, European and regional naval power still matters. But the seizure gives the Houthis a stronger position from which to threaten the approaches to the strait, improve surveillance, shorten some attack geometries and complicate the logistics of their opponents.

ISW-CTP assessed on 10 September that the offensive advances objectives shared by the Houthis and Iran by improving Houthi positions along the southern Red Sea coast. It also cautioned against assuming that every future Houthi decision will be dictated by Tehran. The movement has its own Yemeni political and military objectives, even where those objectives overlap with Iran’s regional campaign against the United States and its allies.

That distinction is important. Iranian support for the Houthis is extensively documented, but strategic alignment is not the same thing as complete command-and-control. A movement with its own agenda can be harder, not easier, to restrain through diplomacy with an external patron.

Perim Island and the geometry of the strait

Perim (Mayyun) Island sits inside the Bab al-Mandab Strait, opposite Yemen’s southwestern coast. Editorial reference image supplied by the author. Image withheld from publication pending rights clearance.

Perim, also known as Mayyun, occupies an unusually sensitive position inside Bab al-Mandab. On 10 September ISW-CTP said regional media were reporting a Houthi seizure of Perim and landings on the Hanish Islands, while noting at the time that it could not independently confirm control of those islands. By 11 September, Associated Press and The Guardian reported that Houthi forces had captured Mayyun/Perim, marking a further escalation after the fall of Mocha.

The military value of the islands is straightforward: positions closer to the shipping lane can support surveillance, small-boat operations and potentially missile or drone attacks at shorter ranges, provided the occupier can sustain ammunition, sensors and logistics. But geography should not be confused with omnipotence. Holding an island does not mean controlling every ship that passes through a heavily watched international chokepoint.

Shipping does not have to stop for the crisis to bite

Commercial shipping is governed as much by risk as by physical obstruction. A strait can remain technically open while insurers raise war-risk premiums, crews refuse voyages, operators reroute vessels and freight rates climb. The Houthis have demonstrated before that missiles and drones can alter commercial behaviour even without physically sealing the waterway.

The movement has said that international navigation through the Red Sea and Bab al-Mandab remains safe and uninterrupted while maintaining restrictions on Saudi vessels. That message is strategically significant: it attempts to present the Houthis not simply as a force capable of disruption, but as an actor claiming the power to distinguish between permitted and prohibited traffic. Whether shipowners and insurers accept that assurance is another matter.

Saudi Arabia’s narrowing margin for manoeuvre

Houthis Claim Attacks on Saudi Energy Sites

• Attack / strike
• Oil field / production
• Refinery / processing plant
• Storage facility
• Gas facility
• Oil / gas facility (storage/transport)
• City / key location

Recent Houthi claims have included attacks against energy and military-related locations in southern Saudi Arabia. Source: editorial reference graphic supplied with the War Report research. Graphic withheld from publication pending rights clearance.

The Red Sea front has become particularly sensitive for Saudi Arabia because of the wider regional energy picture. Saudi crude can be moved west through the East-West Pipeline to Yanbu, reducing dependence on Hormuz. But the value of that bypass diminishes if the western maritime exit itself becomes more dangerous.

The pressure is already visible in production and export data. Saudi Arabia reported to OPEC that crude output fell to 6.238 million barrels a day in August, down about 1.9 million barrels a day from July and its lowest reported level since 1990, according to reporting based on OPEC’s monthly data. The Financial Times has separately reported Saudi crude exports falling to roughly 3.1 million barrels a day, the lowest since at least 2013, amid Houthi threats and disrupted regional routes.

Oil markets have responded accordingly. Brent moved above $100 a barrel after the Mocha advance and was trading above $105 in subsequent reporting. Prices are not a simple referendum on one battlefield event: they also reflect Hormuz, inventories, production shut-ins, expectations of future supply and the risk of a wider war. But the addition of a second threatened chokepoint materially worsens the market’s risk calculation.

MBS turns to Washington

The military setback has also exposed the limits of Saudi Arabia’s attempt to manage the escalation without deeper US involvement. Axios reported on 11 September that Crown Prince Mohammed bin Salman called US President Donald Trump twice as Houthi forces advanced, urging American strikes against the movement. Trump declined direct military action, according to the report, while Washington increased intelligence and targeting support and focused on keeping Red Sea trade routes open.

The US posture is therefore neither full disengagement nor direct entry into another air campaign. The arrival of the US Central Command leadership in Saudi Arabia for urgent coordination underscores how seriously Washington views the threat to the waterway, even as the administration remains wary of expanding the war.

The Mecca defence pact faces its first credibility test

The crisis is also forcing uncomfortable questions on Pakistan and Turkiye. The three countries signed the Mecca Joint Defence Agreement in August, declaring that an armed attack on one member would be regarded as an attack on all. Pakistan’s Defence Minister Khawaja Asif said this week that continued Houthi attacks on Saudi territory could activate the pact.

Yet no joint combat response has been announced. Pakistan subsequently said that no military action had been discussed under the pact. That does not mean the agreement has formally failed; the mechanisms for implementation remain unclear. Politically, however, this is its first real test. The gap between a collective-defence declaration and an actual decision to enter a live regional war is now visible.

Iran, the Houthis and the two-strait problem

For Tehran, the Houthi advance complements a broader pressure campaign against the United States and its regional partners. Iran has already sought leverage through attacks on US forces and through restrictions on shipping around Hormuz. A stronger Houthi position near Bab al-Mandab creates another point of pressure on the opposite side of the Arabian Peninsula.

It would be analytically wrong to say that Iran now controls both straits. It does not. But Iran and an aligned armed movement now have the capacity to generate pressure at both of the Arabian Peninsula’s principal maritime gateways. That is enough to change planning in Riyadh, Washington and global energy markets.

Pakistan, meanwhile, is caught between its defence commitments to Saudi Arabia and its relationship with Iran. Islamabad has urged Tehran to help de-escalate the crisis, while Iranian officials have publicly rejected the proposition that they directly control Houthi decisions. The resulting triangle leaves Pakistan with little room for an uncomplicated policy: it has obligations to Riyadh, reasons to avoid confrontation with Tehran and an interest in preserving a role in regional diplomacy.

What happens next

The next phase will be decided less by rhetoric than by a handful of observable indicators. The first is whether Houthi forces can hold Mocha against counterattack. The second is whether they consolidate Dhubab and the coastline opposite Perim. The third is whether island positions can be supplied and militarised. The fourth is how Saudi Arabia responds: with limited punitive air strikes, a broader campaign or renewed negotiations. The fifth is the behaviour of commercial shipping and insurers.

The humanitarian consequences are already severe. The UN’s Yemen envoy warned on 10 September that the country had entered a new and more dangerous phase, with renewed fighting displacing tens of thousands of people and adding pressure to a population already facing acute food insecurity. Any battle for the southern Red Sea corridor will be fought through towns and communities that have endured more than a decade of war.

The strait to watch has changed

For months, the world’s energy debate has centred on Hormuz. That remains a critical risk. But the fall of Mocha and the reported Houthi gains around Perim mean policymakers and markets can no longer treat Bab al-Mandab as a secondary theatre.

The strategic issue is not whether the Houthis can literally stop every vessel. It is whether they can make the route dangerous enough to alter shipping behaviour, raise costs, constrain Saudi export options and force outside powers to decide how much military risk they are prepared to absorb to keep the waterway open.

That is why Mocha matters far beyond Yemen. A local battlefield collapse has opened a second energy front in a regional war. The question now is not only who holds Yemen’s western coast, but who can credibly guarantee passage through one of the arteries of the global economy.

Key points

Sources and editorial note

This article draws on open-source reporting and battlefield mapping available up to 11 September 2026. Developing battlefield claims are identified as such, and control of terrain should not be treated as equivalent to uncontested control of international shipping. Maps are reproduced here as editorial reference with source attribution.

ISW / Critical Threats Project: Iran Update, 10 September 2026; assessment of the Houthi coastal offensive and reported island operations. https://www.criticalthreats.org/analysis/iran-update-september-10-2026

Al Jazeera: Reporting on the capture of Mocha, the government withdrawal and Houthi statements on navigation. https://www.aljazeera.com/news/2026/9/10/yemens-houthis-seize-strategic-red-sea-city-of-mocha

US Energy Information Administration: Short-Term Energy Outlook data on Hormuz and Bab al-Mandab petroleum flows in 2026. https://www.eia.gov/outlooks/steo/report/global_oil.php

Axios: Reporting on MBS calls to Trump and US-Saudi military coordination. https://www.axios.com/2026/09/11/houthis-yemen-saudi-trump-mbs-strikes

Al Jazeera - Mecca pact: Pakistan’s public position on possible activation of the Mecca Joint Defence Agreement. https://www.aljazeera.com/news/2026/9/9/pakistan-warns-mecca-defense-pact-will-activate-after-houthi-attacks

Associated Press / The Guardian: 11 September reporting on Houthi control of Mayyun/Perim Island and the implications for Bab al-Mandab. https://apnews.com/article/025d052a14d9481258d51009a76d0bd6

Bloomberg HT / OPEC data: Saudi-reported August production of 6.238 million b/d, the lowest reported level since 1990. https://www.bloomberght.com/suudi-arabistan-in-petrol-uretimi-1990-dan-beri-en-dusuk-seviyeye-geriledi-3787828

© 2026 Parrhesia News Media Group. Editorial credit: Parrhesia Editorial Team.