- Lead. Yemen’s Houthi movement declared a naval blockade of Saudi Arabia on July 20, threatening to close the Bab al-Mandeb strait—the Red Sea’s southern gateway—just months after Iran shut the Strait of Hormuz.
- Fact. The Bab al-Mandeb is 29 kilometres wide at its narrowest point; in 2024, approximately 4.1 billion barrels of crude oil—about 5% of global supply—transited it annually. Combined with Hormuz, the two straits handle around 25% of global oil and gas.
- Stake. Two Saudi crude tankers bound for China and India reversed course in the Red Sea on Tuesday following Houthi threats—the first sign that physical oil flows, not just prices, are responding.
The Blockade Declaration
Houthi military spokesman Yahya Saree announced the maritime embargo on Monday, framing it as “an eye for an eye” in retaliation for what the group describes as a Saudi-imposed siege of Yemen lasting more than a decade. A July 13 attack on the runway of Houthi-controlled Sana’a International Airport was cited as a proximate trigger. Saudi Arabia condemned the declaration without specifying its response. The Houthis did not detail how they intend to enforce the blockade—the group’s naval assets are limited relative to the volume of commercial traffic through the strait—but traders and tanker owners have historically responded to Houthi declarations with immediate rerouting, and Tuesday’s tanker reversals confirmed that pattern is repeating. Al Jazeera reported the details of the declaration Monday.
Saudi Arabia’s Exposed Rerouting Strategy
The blockade targets a vulnerability Saudi Arabia created by adapting to the Hormuz closure. The kingdom’s Petroline pipeline—the East-West Pipeline—pumps approximately seven million barrels per day from eastern fields to the Red Sea port of Yanbu. Recent exports from Yanbu averaged four million barrels daily, up from under one million a year earlier, as Saudi shippers rerouted crude away from the Strait of Hormuz following Iran’s February closure. If the Houthi blockade restricts access to the Bab al-Mandeb, that rerouting strategy collapses and Saudi Arabia loses its main export pathway in either direction simultaneously.
The announcement came as the US-Iran war entered a more intensive phase, with US forces striking targets across Iran including Bandar Abbas, Qeshm Island, Shiraz, and Isfahan, and Iran retaliating against US positions in Bahrain, Kuwait, and Jordan. At least three oil tankers caught fire near the Strait of Hormuz during the overnight exchanges reported by US Central Command.
What a Sustained Closure Would Mean
Analysts consulted by Reuters put the combined supply risk in stark terms. The Strait of Hormuz alone accounted for roughly 20% of global oil trade before Iran’s closure; the Bab al-Mandeb handles an additional 5%. Together, a sustained dual closure would represent the largest supply disruption in decades. Saudi crude oil exports had already fallen to record lows for a third consecutive month in May, constraining the kingdom’s ability to use spare capacity as a market stabiliser. The Caspian Pipeline Consortium separately halted loadings at its Black Sea terminal on Tuesday following unrelated tanker attacks, removing a further source of supply from the market.
One analyst offered Reuters a binary prognosis: the Houthi move is either “a last attempt to strengthen the negotiating position” ahead of any resumed Iran-US talks, or the opening of “a more prolonged stalemate, with continued uncertain energy flows, higher oil prices and recurring attacks.” Brent crude settled at $91.05 a barrel on Tuesday, its highest close since June 10.