Houthi Seizure of Mokha and Red Sea Islands

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What Happened

On 10 September, Houthi forces advanced along the southern stretch of Yemen’s west coast and took the Red Sea port of Mokha, along with islands in the Hanish chain north of the Bab el-Mandeb. By 11 September they had also taken Perim Island, which sits in the middle of the strait at its narrowest point, roughly 20 km across.

The offensive followed weeks of intensified fighting along the Houthis’ southern and eastern boundaries. Mokha had been held by National Resistance Forces loyal to Tariq Saleh, a member of Yemen’s Presidential Leadership Council. Those forces were reported to be withdrawing south to Dhubab; the Houthis have already advanced past it.

Houthi spokesmen have framed the campaign as pressure on Saudi Arabia and say the group does not intend to seize the strait. The Houthi-controlled Humanitarian Operations Coordination Center said on 10 September that the Bab el-Mandeb remains open to all traffic except vessels linked to Saudi Arabia. With Perim in Houthi hands, that distinction is now enforceable from the shoreline.

Transits Hold, for Now

Traffic through the Bab el-Mandeb has not measurably changed since Mokha fell. Windward data shows 17 vessels transited inbound between 2100 UTC 9 September and 2100 UTC 10 September, and 13 had transited inbound by 1300 UTC on 11 September. Outbound may be the first count to soften: 24 vessels in the earlier window against 9 by midday on 11 September. The second window is a partial day, and all figures are AIS-based and likely undercount, so the outbound number is a trend to watch rather than a conclusion.

Vessels transmitting in the strait on 11 September included 16 tankers and 33 cargo ships across 19 flags, led by Panama (14), Liberia (5), Barbados (4) and Hong Kong (4), with two Russian-flagged vessels among them.

Why it Matters: the Strait Just Got Cheaper to Threaten

Earlier Houthi campaigns against shipping relied on anti-ship missiles and long-range drones fired from further inland. From Mokha, Dhubab and Perim, the shipping lane is within reach of artillery and other short-range, low-cost systems. That lowers the cost of enforcing a selective blockade against Saudi-linked traffic and frees longer-range systems for other targets.

The coastline also matters for smuggling. Mokha was a working port for Yemeni coast guard operations, which have now lost it. The UN Verification and Inspection Mechanism and Saudi naval forces face more miles of Houthi-held coast to patrol against dhow landings. Windward assesses with high confidence that the Houthis will consolidate Mokha quickly and fold it into existing arms and narcotics routes.

For commercial operators, the exposure question is no longer only about sanctions or spoofing. It is about which flag, ownership chain or cargo affiliation a vessel carries into the strait, and whether that affiliation matches a targeting list that has historically been applied loosely.

What to Watch

The next 48 hours will show whether the Houthis press south. Holding Mokha lets them encircle Taiz and cut the Taiz-Aden road; a continued advance would bring them toward the Gulf of Aden and, potentially, Aden itself. Windward assesses with moderate confidence that the group will first reinforce its coastal gains and prepare for a possible Saudi air campaign paired with a government ground offensive, while public recrimination among government-aligned factions undercuts the chances of an effective counter-offensive.

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