U.S. crude inventories, including strategic reserves, plunged by a record as soaring exports start to erode domestic supply cushions.

The decline of 17.8 million barrels brings crude inventories to the lowest levels in nearly a year, according to data from the U.S. Energy Information Administration. Excluding strategic reserves, nationwide petroleum stocks still fell about 9 million barrels last week.

America has emerged as a major supplier to the world as the war in Iran leaves top buyers in Asia and Europe without access to Middle Eastern barrels. Alongside a demand drop in China and emergency reserve releases across the globe, U.S. exports have been one of the key factors preventing oil prices from spiking further and keeping them near the $100 a-barrel-level. 

Overseas crude shipments have averaged 5.3 million barrels a day so far this month, which if sustained would be the most on record. The U.S. was recently a net-exporter of crude oil for the first time on record.

With the Strait of Hormuz effectively blocked, buyers across the world have scrambled to secure alternative supplies. The chokepoint accounts for about a fifth of the world’s oil flows, meaning that even with workarounds there’s been a significant shortfall of crude supply. 

The U.S. has also tapped its Strategic Petroleum Reserve, which is entirely made up of crude, to help minimize the supply shock. Some of those barrels are being sent overseas to cushion the impact of the war. The flow of strategic reserve barrels into the market climbed to 1.4 million barrels a day last week, the biggest weekly pace on record. 

America’s oil supply cushion is also starting to erode at a time when peak summer driving demand starts to heat up and demand rises. Pump prices in the U.S. have surged since the war and the national average is now above $4.55 a gallon, near the highest since 2022. That is likely to add additional pressure on U.S. President Donald Trump to get oil flowing through the strait again, especially ahead of the midterm elections.