Tankers Slip Through: U.S. Blockade Faces First Real Test. The blockade is live—but the ships are still moving.
At least two U.S.-sanctioned supertankers have entered the Gulf through the Strait of Hormuz this week, raising fresh questions about the effectiveness of Washington’s newly imposed maritime blockade on Iran-linked trade.
Shipping data shows the very large crude carriers RHN and Alicia made successful transits despite the restrictions announced by Donald Trump following failed U.S.-Iran negotiations in Islamabad. The RHN entered the Gulf on Wednesday, while the Alicia passed through a day earlier and is reportedly bound for Iraq.
The U.S. military, led by United States Central Command, has maintained that the blockade is working, saying at least 10 vessels have been turned back and that no ships have “broken through” since operations began. Yet maritime tracking data suggests a more nuanced picture, with some vessels continuing to navigate the corridor under complex or ambiguous circumstances.
Iranian state-linked outlet Fars News Agency claimed that a sanctioned tanker had reached Iranian waters, though it did not identify the vessel. Independent tracking confirms increased tanker activity near the strait, even as other ships—such as the Rich Starry—have reversed course after encountering U.S. enforcement.
The discrepancy reflects the inherent difficulty of policing one of the world’s busiest energy chokepoints. The Strait of Hormuz remains a narrow but critical passage for global oil flows, and even a limited number of successful transits can blunt the impact of enforcement efforts.
Analysts note that Iran may be adapting quickly. Tankers entering the Gulf without cargo, shifting ownership structures, or signaling alternative destinations can complicate interdiction efforts. At the same time, Tehran retains the ability to store oil domestically or reroute exports through informal networks, allowing it to sustain output in the short term.
Washington has signaled it may escalate pressure by imposing secondary sanctions on buyers of Iranian crude—an approach aimed at tightening the financial squeeze as diplomatic talks show tentative signs of resuming.
For now, the early phase of the blockade reveals a familiar reality: maritime sanctions rarely produce airtight results. Instead, they create friction—raising costs, deterring some actors, but leaving enough gaps for determined players to exploit.
The coming days will determine whether the blockade evolves into a more effective chokehold—or settles into a contested standoff where enforcement and evasion move in parallel.
