A tactic long used by Iran to bypass Western sanctions has now been adopted by the United States—this time to keep oil flowing from the Middle East amid a regional crisis. After Iran effectively closed the Strait of Hormuz—triggering the worst disruption to the global energy market ever recorded—the U.S. turned to the very method it had previously condemned: ship-to-ship oil transfers at sea.
A Covert Maritime Operation
According to Reuters, the U.S. military oversaw an extensive, highly secretive oil transfer operation off the coasts of Oman and the United Arab Emirates. The effort enabled Gulf states to continue exporting oil despite Iran’s blockade. The operation began in early May and, based on maritime tracking data and satellite imagery reviewed by Reuters, involved at least 116 vessels.
Stealth at Sea
Transfers took place via ship-to-ship (STS) operations near the Strait of Hormuz, where tankers rendezvoused to load crude oil while underway. To avoid detection, participating vessels operated with transponders disabled, minimal lighting, and careful spacing. Offloading onto larger tankers occurred outside Iranian-controlled waters—a process taking 24 to 40 hours. Empty ships then returned to loading points, while loaded vessels proceeded to their destinations.
A U.S. Apache helicopter shot down on June 9 was reportedly part of this operation, according to Reuters’ analysis of concurrent satellite data showing oil transfers near Oman. While the U.S. government denied direct involvement in such transfers, multiple Reuters sources confirmed American coordination of the effort.
From Sanctions Evasion to Energy Security
For years, Iran relied on STS transfers to obscure the origin of its oil and sustain exports under U.S. sanctions. Today, Washington is using the same technique—not to evade restrictions, but to preserve global energy flows from Gulf producers like the UAE and Kuwait.
Based on satellite imagery and vessel capacity data, Reuters estimates that at least 90 million barrels of crude oil and refined petroleum products have been moved since early May through this specialized network. Though far less than the roughly 20 million barrels per day that previously passed through the Strait of Hormuz, the operation helped prevent a deeper energy crisis.
Companies linked to the UAE’s ADNOC and Kuwait Oil Tanker Company participated in the transfers—underscoring the scale and strategic importance of the network. However, the operation carries significant risks: disabled tracking systems, nighttime maneuvers without lights, and heightened military tensions in a volatile region make it especially hazardous.