The U.S. military recently announced that it conducted a maritime interdiction and "right-of-visit" boarding of the sanctioned stateless tanker Majestic X in the Indian Ocean. This operation indicates that U.S. enforcement against Iranian oil shipments is extending beyond the Strait of Hormuz.

The Department of War revealed this action on Thursday, targeting the tanker previously known as Phonix. This vessel has long been linked to Iran's covert fleet and is accused of facilitating the movement of millions of barrels of sanctioned crude oil since 2023.

"International waters cannot be used as a shield by sanctioned actors," the department stated, emphasizing that U.S. forces would continue their "global maritime enforcement" against vessels aiding Iran.

According to TankerTrackers.com, the interdiction took place at 0201 UTC in the Indian Ocean, within the U.S. Indo-Pacific Command's area of responsibility, at coordinates 5.72N, 86.94E. The tracking group reported that this vessel had delivered about 20 million barrels of Iranian oil while operating under a false Guyanese flag without permission.

This operation is part of a series of aggressive U.S. actions related to what Washington describes as a larger maritime blockade and sanctions-enforcement initiative aimed at Iran’s shipping network.

The Majestic X, also known as Eternity and commonly referred to by its former name Phonix, was sanctioned by the U.S. Treasury in December 2024 under Executive Order 13902, which targets vessels transporting Iranian oil.

At that time, the Treasury linked the tanker to Vision Ship Management LLP and accused it of helping to sustain oil revenues that the U.S. says support Iran’s nuclear, missile, and proxy activities.

This recent boarding seems to be the first confirmed direct U.S. action involving this vessel.

The operation occurred just hours after President Donald Trump issued a warning to U.S. naval forces to destroy any boats that may be laying mines in the Strait of Hormuz. He also noted that U.S. mine countermeasure operations were increasing.

Additionally, it follows U.S. claims that enforcement of the blockade now extends well beyond the Gulf.

U.S. Central Command responded to reports suggesting that Iranian-linked tankers were bypassing the blockade. They stated that 29 vessels had been ordered to turn back or return to port and insisted that examples such as Hero II, Hedy, and Dorena did not escape enforcement.

Instead, CENTCOM reported that two of these tankers are currently anchored at Chabahar in southeastern Iran after being intercepted, while another remains under U.S. Navy escort in the Indian Ocean. TankerTrackers noted that satellite images revealed nine Iranian tankers gathered at Chabahar, an increase from five two days prior, suggesting growing congestion as enforcement pressure mounts.

The boarding of Majestic X occurs amid rising maritime tensions.

This week, Iran seized two MSC containerships trying to exit the Persian Gulf, showing that the waterway remains contested, despite President Trump's recent assurance that the strait was "open."

Meanwhile, the U.S. has intensified its interdictions involving Iranian-linked or sanctioned vessels, including the recent boarding of the tanker Tifani in the Indian Ocean, and previous actions against ships viewed as challenging the blockade. This indicates increased pressure from both sides of the maritime route.

Overall, these efforts suggest that maritime enforcement is shifting from localized interdictions to a broader campaign that extends from the Strait of Hormuz into the wider Indian Ocean. This situation raises the stakes for shipowners, insurers, and energy markets beyond the chokepoint itself.