https://heathercoxrichardson.substack.com/p/september-10-2026

Letters from an American
September 10, 2026
Heather Cox Richardson
Sep 11, 2026

We woke up today to news that Yemen’s Iran-backed Houthi militants have taken control of the city and seaport of Mocha and much of the shoreline of the Red Sea near the Bab el-Mandeb strait, another chokepoint for world trade including trade in oil. With the Strait of Hormuz largely closed, Saudi Arabia has relied for seagoing transport on the Red Sea route that empties into the Arabian Sea and the Indian Ocean.

As Diana Roy of the Council on Foreign Relations wrote in July, the Red Sea is one of the most important routes for global shipping. It carries twelve to fifteen percent of the global maritime trade every year, worth about $1 trillion. The waterway extends about 1,400 miles from the Suez Canal—which connects it to the Mediterranean Sea—at the northern end to the Bab El-Mandeb strait in the south.

The Iran-backed Houthis are in a struggle against the Saudi Arabia–backed Yemeni government. A fragile truce has been in place since 2022, but clashes between the two forces have escalated for weeks, and on Tuesday, September 8, Houthi attacks on Saudi targets started fires at oil facilities and wounded more than 70 people.

We woke up today to news that Yemen’s Iran-backed Houthi militants have taken control of the city and seaport of Mocha and much of the shoreline of the Red Sea near the Bab el-Mandeb strait, another chokepoint for world trade including trade in oil. With the Strait of Hormuz largely closed, Saudi Arabia has relied for seagoing transport on the Red Sea route that empties into the Arabian Sea and the Indian Ocean.

As Diana Roy of the Council on Foreign Relations wrote in July, the Red Sea is one of the most important routes for global shipping. It carries twelve to fifteen percent of the global maritime trade every year, worth about $1 trillion. The waterway extends about 1,400 miles from the Suez Canal—which connects it to the Mediterranean Sea—at the northern end to the Bab El-Mandeb strait in the south.

The Iran-backed Houthis are in a struggle against the Saudi Arabia–backed Yemeni government. A fragile truce has been in place since 2022, but clashes between the two forces have escalated for weeks, and on Tuesday, September 8, Houthi attacks on Saudi targets started fires at oil facilities and wounded more than 70 people.

The Yemeni government told Reuters that Iran’s Revolutionary Guard Corps (IRGC) have guided the Houthi advance, and according to Zachary Cohen, Katie Bo Lillis, and Kylie Atwood of CNN, U.S. officials think that hundreds of IRGC officers are currently in Yemen working with the Houthis to shut down the Bab el-Mandeb. The journalists note that CNN has previously reported that in case U.S. negotiations were unsuccessful, Iran had planned an economic “nuclear option”: closing the Bab el-Mandeb.

Cohen, Lillis, and Atwood reported this afternoon that more than 100 U.S. military advisors are in Saudi Arabia as part of a new joint forces command, providing the Saudis with intelligence and helping them find Houthi targets.

The sources who told the journalists about the joint effort emphasized that the U.S. routinely shares intelligence with the Saudis and that it is neither participating directly in the strikes nor providing operational support. Still, U.S. airstrikes on the Houthis in 2025 killed 153 civilians and wounded 243 others in Yemen in 2025.

The price of oil jumped to $109 a barrel, and U.S. gasoline rose to an average of about $4.28 a gallon. GasBuddy said the national average price of diesel had hit $6.00 for the first time in history. Just a year ago, the national average was about $3.70.

GasBuddy issued a statement, saying: “While gasoline gets the headlines, diesel is the fuel that moves the economy, powering the freight trucks, trains, agricultural equipment, and construction machinery behind nearly everything Americans buy. That means its impact reaches far beyond the transportation sector. As diesel climbs, higher supply chain costs work their way into the price of groceries, household goods, deliveries, and countless other products families rely on every day, even for households that never fuel a diesel vehicle.”

GasBuddy’s head of petroleum analysis, Patrick De Haan, said the new record “will be a particularly painful one for the economy” and is “likely to reignite inflation up and down the supply chain.” He continued: “I suggest Americans anticipate a costlier holiday season, as it appears diesel prices could continue climbing as geopolitical tensions continue to remain a main factor.”

While all this was going on, tonight President Trump attended the second day of his Dallas rally to fire up his base before the midterm elections. There, a video from the Republican National Committee intoned: “And on June 14th, 1946, God looked down on his planned paradise and said, ‘I need a caretaker,’ so God gave us Trump.”