Global oil prices climbed above $100 a barrel on September 9, 2026, due to escalating warfare involving the United States, Iran, and Yemen’s Houthi. Fears that the Middle East could lose even more of its ability to supply world energy markets have increased due to recent attacks on oil infrastructure in Saudi Arabia.

Brent crude, the principal international benchmark, reached about $100.66 per barrel, while U.S. West Texas Intermediate rose to approximately $95.77. The increase reflects not simply speculation about future conflict but an increasingly serious disruption of the transportation system that carries Persian Gulf oil to customers around the world.

At the center of the increase in oil prices is access to the Strait of Hormuz, which is now the main point of contention between the U.S. and Iran. U.S. Energy Information Administration data illustrate how dramatically that trade has been disrupted. Oil and petroleum-liquid shipments through Hormuz averaged about 21.6 million barrels per day during the fourth quarter of 2025, but fell to only 4.9 million barrels per day during the second quarter of 2026 following the outbreak of fighting.

Conditions had begun improving. Before hostilities intensified again on August 30, approximately 8 million to 9 million barrels per day were moving through Hormuz. But according to estimates cited by Reuters, recent flows have fallen to below 2 million barrels per day. Renewed U.S.-Iranian attacks have contributed directly to the decline. American forces recently struck several Iranian oil tankers, while Iran attacked ships and a U.S. military base in Jordan. Attacks on commercial vessels have made tanker operators increasingly reluctant to enter the region.

Even when tankers are willing to make the voyage, moving oil has become enormously more expensive. War-risk and cargo-insurance premiums for ships passing through Hormuz can now add $10 million to $20 million to the cost of individual voyages, according to an Emirates National Oil Company executive. Those expenses eventually filter through the energy system in the form of higher crude, gasoline, diesel, and transportation prices.

The crisis became more dangerous when Iran-aligned Houthi forces in Yemen attacked Saudi Arabia on September 8. Missiles and drones struck or targeted energy facilities around Jazan, Abha and Najran, causing fires and forcing some operations to halt temporarily. Seventy-three people were reported injured.

The Houthi-led attacks are particularly important because Saudi Arabia has been using its East-West pipeline to move oil toward the Red Sea, avoiding Hormuz. As Hormuz traffic collapsed earlier this year, petroleum flows through the Bab el-Mandeb near Yemen increased substantially. Houthi attacks threaten one of the principal alternative routes Saudi Arabia has used to keep oil reaching world markets.

The global energy system is being squeezed from more than one direction. Gulf producers face difficulty moving oil through Hormuz, while Saudi Arabia’s alternative Red Sea infrastructure now faces growing military threats. Physical oil supplies and refined fuels have become more expensive. European diesel futures were trading around $199 per barrel on September 9.

Oil prices have already demonstrated how sensitive markets are to the conflict: Brent fell as low as $69 in early July after hopes for U.S.-Iranian de-escalation, only to climb back above $100 as fighting resumed. If attacks further restrict Hormuz or seriously damage Saudi production and export infrastructure, prices could rise considerably higher. Higher petroleum costs would then spread through transportation, manufacturing, agriculture, and consumer prices worldwide, increasing inflation and potentially slowing global economic growth.