The Houthis’ blockade of the Bab al-Mandeb strait couldn’t have come at a worse time for the oil market. The threat alone has persuaded some ships to abandon plans to exit the Red Sea heading south.

An effective blockade would create a new front in the war with Iran, potentially requiring US military intervention that could erode the ability to escort vessels through the Strait of Hormuz. It could also prevent Saudi diesel reaching Europe at a critical time. Oil prices have already surged more than $20 a barrel this month, briefly rising above $95 Wednesday for the first time since early June.

Bab al-Mandeb is just 14 miles wide at its narrowest point, about 40% narrower than Hormuz, and handles roughly 6.2 million barrels of oil per day. Saudi Arabia has diverted 4–5 million barrels via Yanbu, but a full blockade could push prices up an additional $5 to $10 a barrel, potentially exceeding $100.

If ships cannot transit the Red Sea southward, they must go north through the Suez Canal, forcing Saudi oil to detour to Asia via the Mediterranean instead of the Indian Ocean, further tightening supply.