U.S. Prepares to Board Iran-Linked Ships Worldwide

TL;DR

U.S. military plans to board and seize Iran-linked oil tankers worldwide in coming days to expand naval pressure.
U.S. has turned back 23 ships from Iranian ports; targets include dark fleet vessels carrying 1.6 million barrels a day of Iranian oil mostly to China.
Aims to force Iran to reopen Strait of Hormuz and concede on nuclear program amid expiring cease-fire and stalled talks.

The story at a glance

U.S. officials say the military is ready to board Iran-linked ships in international waters beyond the Middle East, as part of the Trump administration's "Economic Fury" campaign. Key figures include Gen. Dan Caine, chairman of the Joint Chiefs, Defense Secretary Pete Hegseth, and Treasury Secretary Scott Bessent, who expanded sanctions on vessels tied to Iranian oil magnate Mohammad Hossein Shamkhani. This comes now after Iran attacked commercial vessels in the Strait of Hormuz on Saturday and recent talks in Pakistan failed, with a temporary cease-fire set to expire next week. The U.S. has blockaded Iranian ports since earlier this month in response to the ongoing war that began with an Israeli airstrike in late February.

Key points

U.S. Central Command has already turned back 23 ships seeking to leave Iranian ports as part of the naval blockade.
Targets include Iranian-flagged vessels, dark fleet ships evading sanctions with Iranian oil, and any providing material support to Tehran, operable by U.S. Indo-Pacific Command.
Iran attacked several commercial vessels Saturday while declaring strict control over the Strait of Hormuz, despite its foreign minister's recent claim the strait is open.
President Trump claims Iran agreed to hand over its highly enriched uranium stockpile, a claim Iran rejects; negotiations also cover uranium enrichment limits and release of frozen Iranian funds.
Treasury expanded sanctions Wednesday on ships and companies controlled by Mohammad Hossein Shamkhani, son of a top Khamenei adviser killed in February.
U.S. plans to prosecute buyers and sellers of sanctioned Iranian oil; past successes include seizing Venezuela-linked tankers in Atlantic and Indian oceans.
Cease-fire expires next week; both sides prepare for possible resumption but prefer economic leverage over ground troops or strikes on power plants.

Details and context

The push escalates after failed talks in Pakistan, with Iran retaining thousands of missiles despite heavy bombing of its defense industry. U.S. forces are "maximally postured" but avoid ground troops due to casualty risks and public opposition; striking power plants remains an option but could prompt Iranian retaliation against Saudi and allied energy sites.

Most Iranian crude exports, about 1.6 million barrels a day, go to small Chinese "teapot" refineries; the boarding plan warns Beijing while disrupting illicit trade. This builds on U.S. experience interdicting sanctioned vessels globally, using military, Justice Department, and Coast Guard coordination.

Legal expert Mark Nevitt calls it a "maximalist approach," using blockade, global seizures, and contraband crackdowns to maximize pressure short of full war.

Key quotes

"The U.S. ‘will actively pursue any Iranian-flagged vessel or any vessel attempting to provide material support to Iran,’... ‘This includes dark fleet vessels carrying Iranian oil.'" – Gen. Dan Caine, chairman of the Joint Chiefs of Staff.
"It’s a maximalist approach. If you want to put the screws down on Iran, you want to use every single legal authority you have to do that." – Mark Nevitt, associate professor of law at Emory University.

Why it matters

Escalating naval actions worldwide heighten risks to global oil trade through chokepoints like the Strait of Hormuz and potential disruptions to 1.6 million barrels a day of exports. For energy markets, shipping firms, and buyers like Chinese refiners, it means higher costs, rerouting, and legal exposure from sanctions enforcement. Watch for boarding outcomes, cease-fire extension talks, or Iranian retaliation at sea, though officials see economic pressure as the preferred path to a deal.