Commercial traffic through the Bab al-Mandab Strait dropped to 11 cargo vessels on Sunday, the lowest single-day count in months, following Houthi missile and drone strikes on Saudi Aramco facilities at Jizan and Yanbu. Transits through the Strait of Hormuz remained severely depressed across the same weekend, with fewer than 10 cargo vessels crossing on each of the three days. The two chokepoints are now constrained simultaneously for the first time in the current conflict.
What the Vessel Counts Show
Seven of the 11 vessels transiting Bab al-Mandab on Sunday were oil tankers, three of them inbound into the Red Sea. The composition matters: inbound tanker traffic into a strait under an active declared blockade indicates either committed voyages that could not be economically diverted, or operators calculating that non-Saudi cargo carries acceptable risk.
Hormuz volumes tell a different story. Seven vessels crossed on Sunday, including three Iran-linked product tankers outbound from the Gulf. Saturday produced only three transits — a VLCC inbound to Qatar for crude, an LPG carrier bound for Ruwais, and a naphtha cargo routed to Japan — and all three sailed with transponders switched off. Friday recorded seven, weighted toward outbound movements. AIS silence on the entirety of a day’s traffic is the operational signature of crews treating identification itself as a targeting risk, not a compliance formality.
Neither count reflects a full stoppage. Both reflect a market in which only cargoes with no viable alternative are moving.
The Yanbu Dependency Is the Real Target
Jizan is a refinery. Its 400,000 barrels per day of throughput can be substituted from stockpiles, and its loss does not remove barrels from the export market. Yanbu is categorically different. It is the terminus of the East-West Pipeline running roughly 1,200 kilometres from the Gulf coast to the Red Sea, and it became the kingdom’s primary crude export outlet once Hormuz was effectively closed. It handled 92 per cent of Saudi seaborne crude exports in June.
Riyadh built that redundancy precisely to survive a Hormuz closure. The redundancy has now been located and struck. Volumes moving out of Yanbu southbound through Bab al-Mandab had surged to roughly 3.5 million barrels per day in June, against a few hundred thousand a year earlier — the entire increase a product of Hormuz displacement. Every one of those barrels must exit through a strait the Houthis have declared closed to Saudi-linked shipping.
The alternative is northbound through Suez and around the Cape for Asian buyers. A Yanbu-to-South Korea voyage runs about 24 days via Bab al-Mandab and roughly 54 days via the long route. That is not a workaround; it is a four-week penalty applied to term contracts sold at fixed monthly prices to buyers in China, India, and Japan.
Assessment
The strategic picture is a pincer rather than two separate disruptions. Hormuz constrains Gulf-coast loading. Bab al-Mandab constrains the Red Sea bypass that was supposed to compensate. Saudi Arabia retains physical export capacity at Yanbu but faces a degraded ability to move that capacity to its customers at commercially viable transit times.
The daily vessel counts are the most responsive indicator available, but they lag the decision-making that produces them. Charterers commit days ahead. A count of 11 on Sunday reflects risk assessments made the previous week, before the Jizan and Yanbu strikes were confirmed.
Indicators to Watch
Transponder discipline in the southern Red Sea. Widespread AIS shutdown in Bab al-Mandab, matching the pattern already visible in Hormuz, would signal that operators have concluded identification is a liability across both chokepoints.
Yanbu loading rates against pipeline throughput. A sustained divergence — crude arriving at the terminal faster than it departs — indicates tank-top constraints building toward upstream production cuts.
Southbound versus northbound splits out of Yanbu. A structural shift toward Suez routing confirms that operators have written off Bab al-Mandab rather than treating the closure as temporary.
War-risk premiums for Saudi-linked hulls specifically, as distinct from general Red Sea rates. Divergence between the two prices the effectiveness of the Houthi declaration as a discriminating instrument rather than a blanket threat.
U-turn counts at both approaches. Vessels reversing course after committing to a transit corridor are the clearest available measure of real-time threat perception, and they moved first in the days preceding the Jizan strike.