Brent Crude Holds Near $104 as US Sanctions 17 Iranian Tankers

A muted reaction to a major escalation

On October 8, Washington announced what it described as its heaviest blow yet against Iran's oil export network. Oil traders reacted calmly. The Treasury Department sanctioned individuals, networks and 17 vessels that carry Iranian crude, refined products and petrochemicals. The action falls under "Operation Economic Outcast," a campaign meant to cut off money Tehran uses for its war with the United States, its missile program, cyberattacks and the Islamic Revolutionary Guard Corps.21 A Treasury official said the designations neutralized "the vast majority" of Iran's shadow fleet.22 The State Department added its own designations. Together, the two actions covered 22 vessels, 27 companies or entities, and six individuals.24

The price barely moved. Brent futures opened at $103.73 on October 92 and finished that day around $104.54, down 0.17%.6 By Monday, October 12, Brent had slipped below $104. Trading Economics said investors also looked past deadly Houthi attacks on Riyadh's King Khalid International Airport, even though President Trump was weighing joint retaliation with Saudi Arabia.1 Over the past month the benchmark is down about 1.6%, but it is still about 64% higher than a year ago.1

The market's reaction makes sense. The sanctions mostly put on paper something the US Navy had already done by force.

Why the sanctions changed little for prices

The US reimposed its blockade of Iranian ports on July 14, after a memorandum of understanding meant to end the war fell apart.21 Treasury officials say Iran has stopped loading and unloading crude tankers altogether.21 Kpler data cited by CNBC show no Iranian crude loaded for export since August 25.28 The market had already priced in the loss of Iranian barrels. The new designations go after the last cargoes still at sea, not new supply.

Even those cargoes are small. Treasury puts Iranian crude on tankers outside the blockade at about 20 million barrels, near Singapore, Malaysia and China. Global demand is roughly 100 million barrels a day.22 Kpler's estimate is lower still: about 8 million barrels on the water, down from nearly 90 million in mid-July. Kpler analyst Homayoun Falakshahi expects those cargoes to be unloaded by around October 18.29 The two figures differ, but both describe a stockpile that is almost gone. Neither describes a meaningful amount of supply being removed from the market.

CNBC also noted that this action alone is not expected to cause major changes in Iran's economy. Treasury itself called the targets the "remnants" of the shadow fleet.28 The vessels named show how small the remaining trade is. Treasury said the Comoros-flagged Paritosh carried more than 100,000 barrels of Iranian bitumen this year, and the Panama-flagged Bitu more than 170,000 barrels.24 Those are minor volumes in a market of 100 million barrels a day.

The real impact is on Iran's revenue

The sanctions matter more for Iran's finances than for oil prices. Falakshahi told Iran International that if the blockade holds, Iran's revenue from crude and condensate exports could fall to zero by mid-December. That would be a first. Iranian oil kept reaching buyers through the 1979 revolution, the Iran-Iraq war and every earlier round of sanctions.29 He estimated Tehran could lose $3 billion to $6 billion in oil income each month. Chinese refiners usually take one to two months to pay, so the last payments would arrive around mid-December.29

Experts at a Washington panel agreed that the pressure is real but doubted it will force concessions. Former Treasury official Kerri Bitsoff said this campaign differs from earlier ones because it focuses on enforcement and on financial intermediaries. Patrick Clawson of the Washington Institute warned of severe economic hardship for Iran this winter, made worse by damage to its gas infrastructure.29 The political timing adds uncertainty. Trump has said the US will not strike Iran before the November 3 midterm elections23, and Iran International reports that the pledge has prompted calls inside Iran to act first.29 In practice, the market is betting on a military escalation, not on any further loss of Iranian barrels.

Diesel shortages are driving prices more than Iran

Iran is not the main reason oil prices are high. The bigger problem is shortages of refined fuel, especially diesel. The EIA's October Short-Term Energy Outlook raised its fourth-quarter Brent forecast to $105 a barrel, up $14 from September. It cited attacks on Saudi Arabia's East-West pipeline and "extreme tightness" in diesel markets, which pushes refiners to buy more crude.11 Brent spot averaged $114 in September, $23 higher than in August. U.S. retail diesel averaged $6.29 a gallon and gasoline $4.35.11 East Coast distillate inventories were 32% below their five-year seasonal average in September.11

Futures prices and physical prices are telling different stories. Brent futures have held in the low $100s. But EIA spot data published through FRED put Brent at $125.44 on October 6, after a reading of $135.51 on October 2.4 On that spot basis, Brent traded $29.20 above WTI, the widest gap in records going back to 1987.10 Our reading is that the calm in futures understates how tight physical supply is. Prompt barrels and refined products are scarce, even though Gulf exports are recovering.

That recovery is real. Goldman Sachs estimated that Gulf oil exports climbed back to 23.3 million barrels a day in late September, in line with their 2025 average. JPMorgan's 10-day average was lower, at about 89% of 2025 levels.26 The banks disagree on how far supply has recovered, but both see it improving. That helps explain why sanctions news no longer moves crude much. Meanwhile, the White House has urged the EU to release emergency diesel stocks and is considering a red-dyed diesel measure to ease prices before the midterms.26 Those are signs that refined fuel, not crude supply, is the political pressure point.

The data center link runs through natural gas

AI data centers have little direct effect on crude prices, because they mostly run on electricity made from natural gas. Gas and oil prices have moved in very different directions this year. Henry Hub gas traded near $3.12 to $3.18 per million British thermal units in early October12, while Brent stayed above $100.1 The EIA forecasts Henry Hub at $3.16 for 2027.11

Demand forecasts, however, keep rising. BloombergNEF now projects that gas burned to power U.S. data centers will rise by about 15 billion cubic feet a day through 2035. That is more than double its December estimate, and it already assumes many announced projects will never be built.13 BloombergNEF expects gas to supply 69% of the power for new grid-connected data centers. It says producers would need about 11 billion cubic feet a day beyond their planned growth to meet demand from both data centers and LNG exports.18 Goldman's October update raised its forecast for U.S. data center capacity to 64 gigawatts by the end of 2026 and 90 gigawatts by the end of 2027. Morgan Stanley expects gas to meet a smaller share of AI-driven demand than Goldman does.12 The EIA forecasts commercial-sector electricity demand, which includes data centers, to grow 2.8% in 2027.11

This is where the oil shock connects to data centers. Much U.S. gas is a byproduct of oil drilling in the Permian Basin. Energy executive Stuart Turley argued that if oil fell below roughly $70 a barrel for a sustained period, new Permian drilling could slow and reduce that byproduct gas. That would push supply toward more expensive gas-focused drilling.13 So $100-plus crude may actually be helping cheap gas for the AI buildout, because it keeps oil drillers busy and associated gas flowing. If the Iran crisis ends and crude falls back toward the EIA's 2027 forecast of $8411, the gas cushion behind data center power could shrink.

Wood Mackenzie has already said that "the decade of cheap Henry Hub gas is coming to an end"18, and BloombergNEF reports that the cost of building new combined-cycle gas plants has jumped 66%.19 Costs are also reaching households. Residential electricity prices are rising even where wholesale power prices have fallen, because grid and capacity costs are going up.17

The outlook

The latest sanctions do little to change the oil market but a lot to change Iran's finances. Prices will depend on a few things: whether the Houthi attacks on Saudi infrastructure escalate, how quickly diesel stocks recover, and whether Washington keeps its promise not to strike Iran before November 3. Over the longer term, the bigger structural shift is the race to secure gas for data centers. That story depends partly on oil staying expensive enough to keep the Permian drilling.