Pentagon: US forces board sanctioned oil tanker

U.S. forces have boarded an oil tanker previously sanctioned for smuggling Iranian crude oil in Asia, the Pentagon announced Tuesday, expanding enforcement actions against vessels linked to Iran beyond the Middle East.

The operation against the M/T Tifani occurred “without incident” in the Bay of Bengal, between India and Southeast Asia, according to defense officials. A U.S. defense official, speaking on condition of anonymity due to the ongoing operation, confirmed the vessel was carrying Iranian oil when captured.

Military leaders will determine the tanker’s fate within the next four days, potentially towing it to the United States or transferring it to another country’s custody.

This interdiction represents the latest move in Washington’s intensifying maritime campaign to enforce sanctions against Iran, targeting vessels suspected of transporting Iranian goods ranging from weapons and oil to metals and electronics. The operation comes as the U.S. maintains a naval blockade of Iranian ports while simultaneously extending a fragile ceasefire in the ongoing conflict.

Just days earlier, U.S. Navy forces attacked and seized an Iranian-flagged cargo ship called the Touska that allegedly attempted to evade the blockade. President Trump stated that an American destroyer had fired on the vessel, damaging its engine room.

The Pentagon described the Tifani as “stateless” despite its Botswana registration. In their statement, defense officials emphasized: “As we have made clear, we will pursue global maritime enforcement efforts to disrupt illicit networks and interdict sanctioned vessels providing material support to Iran — anywhere they operate. International waters are not a refuge for sanctioned vessels.”

This expanded enforcement strategy was previously signaled by Gen. Dan Caine, chairman of the Joint Chiefs of Staff, who told reporters last week that U.S. forces would “actively pursue any Iranian-flagged vessel or any vessel attempting to provide material support to Iran” beyond Iranian waters and the U.S. Central Command area. He specifically mentioned operations in the Pacific and targeting vessels that departed before the blockade was established at the Strait of Hormuz, a critical waterway for global energy shipments.

The U.S. military has outlined an extensive list of goods considered contraband, stating it will board, search and seize such items from merchant vessels “regardless of location.” A notice published Thursday declared that any “goods that are destined for an enemy and that may be susceptible to use in armed conflict” are “subject to capture at any place beyond neutral territory.”

These aggressive maritime actions have raised questions about the status of the two-week ceasefire between the U.S. and Iran. Jason Chuah, a law professor at the City University of London and the Maritime Institute of Malaysia, described the situation as “an awkward space where the law doesn’t give you a clean yes-or-no answer” on whether the ceasefire has been violated.

“The United States seems to take the line that the conflict never fully switched off — that there is still a state of armed conflict,” Chuah explained. “By saying that, it can keep doing things like enforcing a blockade and even using limited force at sea.” Iran, meanwhile, appears to interpret the ceasefire as a pause on all hostile acts.

Iranian Foreign Minister Abbas Araghchi condemned the U.S. blockade as a breach of the ceasefire, stating that “striking a commercial vessel and taking its crew hostage is an even greater violation.” Iran’s U.N. Mission has formally requested that the U.N. Security Council and Secretary-General António Guterres condemn the U.S. for seizing the Touska and its crew.

While the U.S. had previously established a blockade against sanctioned oil tankers linked to Venezuela, it had never fired on those vessels until now.

Chuah noted that blockades and limited attacks on vessels can be lawful during wartime, with merchant ships becoming legitimate targets if they contribute to military actions, carry contraband, or are incorporated into enemy logistics. However, he said it’s more difficult to prove that a vessel like the Touska is realistically contributing to military action against the U.S.

“The whole dispute really turns on a deceptively simple question: Did the ceasefire actually suspend the right to use force?” Chuah said. “If it did, then firing on vessels or seizing them is very hard to square with the United Nations Charter.”

Mark Cancian, a retired Marine colonel and senior defense adviser with the Center for Strategic and International Studies, pointed out that the terms of the ceasefire were never clearly defined. “Trump announced it. The Iranians agreed. But there’s no formal agreement,” Cancian said. “So whether it broke the ceasefire or not depends on your perspective… Nothing was written down.”

Michael O’Hanlon from the Brookings Institution argued that the U.S. did not violate the ceasefire since it was specifically limited to bombing Iran, not the blockade. “We agreed to stop dropping bombs on them, and that’s the basic thing they wanted,” O’Hanlon said, adding that the U.S. still needed to enforce the blockade “if you’re going to make it mean anything.”