U.S. forces are stepping up efforts to disrupt the long-running covert oil trade between Iran and China, targeting a network of aging tankers and intermediaries used to evade sanctions.
U.S. personnel boarded a sanctioned tanker, the MT Tifani, in the Indian Ocean this week, according to The Wall Street Journal, part of a clampdown on what analysts describe as a shadow fleet sustaining Iran's oil exports.
The vessel, which had loaded crude at Iran's Kharg Island earlier this month, has made repeated trips to Chinese ports in recent years and was operating without a recognized national flag at the time of the interception.
The action comes as the United States expands enforcement beyond Iranian ports, raising pressure on a system that has allowed Tehran to continue exporting oil despite sanctions.
Raymond Powell of Stanford University's SeaLight project said the move signals a shift in enforcement.
"It's like you've been driving the same road every day and you see one person in the HOV lane over and over and over, and finally you see one that gets pulled over," he said.
Analysts estimate more than 500 vessels are involved in the shadow fleet supporting Iran's oil trade, using tactics such as ship-to-ship transfers in waters near Malaysia and Indonesia to obscure the origin of crude shipments.
Those practices help explain why China's official customs data show no imports of Iranian crude since 2022, even as analysts estimate the country continues to import roughly 1.4 million barrels per day, or about 12% of its total supply.
Large volumes of Iranian oil are already positioned offshore.
More than 160 million barrels are stored on tankers, with about 140 million barrels outside the immediate blockade zone, providing a buffer that could sustain exports and support Iran's economy.
The United States has also taken action against other vessels linked to the trade, including a recent seizure of a ship with ties to China.
President Donald Trump referenced that action in an interview Tuesday.
"We caught a ship yesterday that had some things on it, which wasn't very nice," he said. "A gift from China perhaps, I don't know, but I was a little surprised, because I have a very good relationship and I thought I had an understanding with President Xi [Jinping]."
China has rejected any connection to the seized vessel and continues to oppose U.S. sanctions, which it considers illegitimate.
Powell said the expanded enforcement could alter behavior across the network.
"If you're on a flag of convenience or in this case, a stateless tanker, you now have to think about this other thing which is you could be out in the middle of the Indian Ocean and all of a sudden helicopters could drop from the sky," Powell said.
Jim Mishler ✉
Jim Mishler, a seasoned reporter, anchor and news director, has decades of experience covering crime, politics and environmental issues.
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