The Justice Department is moving to bring back a centuries-old maritime legal tool as it seeks to accelerate U.S. efforts to claim Iranian oil tankers seized during the war with Iran. But legal specialists in maritime law warn that the strategy may run into significant obstacles.
The chief federal prosecutor for the Southern District of Texas confirmed last month that his office is helping revive prize law, a highly specialized legal framework that has not been used on a regular basis since the Spanish-American War. The department now intends to rely on that body of law in disputes over whether ships and tankers captured at sea since the start of the Trump administration were lawfully seized.
“Our national security interests may require the United States military to seize vessels or cargo supporting the enemy during military conflict,” Aaron Reitz, the U.S. attorney in the Southern District of Texas, said in a statement. “If that happens, our federal courts must be ready to adjudicate the disposition of these captured vessels and cargo.”
“Prize law is an ancient body of maritime law — already codified in statute but which we are now reviving — that sets the rules for how seized maritime property is condemned, returned, or disposed of,” Reitz continued.
Prize law, whose formal roots date to the early 1600s, could give the administration a faster route than civil asset forfeiture, which often becomes mired in lengthy court proceedings. Instead, the process would allow the government to seek legal condemnation of captured Iran-linked vessels through a more streamlined mechanism. A judge handling the seizure would still need to determine that the United States had met the required legal standard before awarding the vessel as a prize.
Under existing federal law, U.S. district courts can hear prize law cases after the military seizes a vessel. To prevail, the Justice Department and the Pentagon would need to show that the captured ship was carrying contraband, transporting enemy fighters, operating under enemy control, relying on fraudulent paperwork or trying to evade a blockade.
If the Justice Department’s approach withstands expected legal challenges, a court could grant the United States the oil or other cargo found aboard seized Iran-linked ships. That cargo could then be sold, with the proceeds likely directed to the Treasury Department.
The effort to revive prize law was first reported by Bloomberg Law. It marks the third time the Trump administration has turned to a dormant or rarely used legal mechanism to try to move more quickly on policy priorities. In July, the Justice Department attempted to use the Alien Terrorist Removal Court, a tribunal created in 1996 that had never previously been used, to hasten deportations of suspected “alien terrorists.” Last year, the administration deported Venezuelan migrants accused of ties to the Tren de Aragua gang under the Alien Enemies Act of 1798, a law that had not been invoked since World War II.
But international and maritime law experts say the administration’s potential application of the centuries-old laws could backfire in the short term and the long term.
Michael Sturley, a maritime law professor at the University of Texas School of Law, said that 1789 federal law gives district courts and judges in the U.S. jurisdiction over potential prize law cases, but the seized vessel would have to be physically moved to the district — in this case, potentially the port of Houston.
“You know, you go back to the Revolutionary War and the War of 1812, prize courts were huge,” Sturley said. “Back when we didn’t have much of a navy, we sort of outsourced a lot of the functions that you would expect a navy to serve, and would issue letters of embark to private individuals, authorizing them to go out and harass enemy shipping. And the incentive for the private individuals was they got to keep what they killed.”
Sturley said in previous iterations, the prize would be split between the government, which commissioned the privateers, and the captains and crews who operated the boat that had seized the belligerent vessel — a ship belonging to a nation that was actively engaged in conflict with the United States.
Ian Ralby, a maritime law and security expert, says he doesn’t see “any problem with reviving the law of capture and prize.”
“We’ve already seen the revival of blockade. We’ve seen the revival of the law of contraband. So all of these, like naval warfare doctrines that were seemingly collecting dust on the shelf, are available and applicable,” said Ralby, the president of Auxilium Worldwide, a charitable nonprofit that in-part focuses on ocean governance.
But he believes the Trump administration’s attempt to apply prize law poses “some pretty significant domestic and international legal challenges,” specifically in the Middle East, and South America, where the Trump administration has seized Iranian and Venezuelan-linked tankers that are carrying what the administration could argue is contraband worth seizing.
“The question is more of a domestic issue for the United States and a consistency issue in articulating what it’s actually doing,” given President Trump’s repeated reversals on military and economic positions in dealing with the ongoing conflict with Iran, Ralby said.
He pointed to the U.S. seizure of an Iranian-flagged cargo ship known as the Touska in May, after it attempted to bypass the U.S. blockade of Iranian ports and vessels. Iran condemned the ship’s seizure as “piracy” and urged the United Nations to intervene.
“The claims were simultaneous — that this was sanctions enforcement, which is a peacetime construct — and blockade enforcement, which is a law of naval warfare construct. You can’t have both,” Ralby said.
Thomas Lee, an international law professor at Fordham University School of Law said that while it’s possible using prize law could streamline the process, prosecutors may run aground in cases involving vessels that the U.S. has alleged are affiliated with countries like Iran or Venezuela but sail under the flag of a different country. He suggested that the third nation could challenge the legality of the seizure because Congress has not authorized a war with Iran.
Lee added that if the U.S. were to reactivate prize law, it’s likely that adversaries could attempt to interdict American-flagged ships in the future.
“Twenty, 30, 40, 50 years from now, definitely, right?” Lee said. “I mean, the Chinese could be doing it in the South China Sea, and it just doesn’t seem like a very prudent idea for the long term.”
Another challenge, Lee said, is physically bringing the vessels to a U.S. port.
“The whole premise of the prize jurisdiction was that you actually had the ship and the cargo physically present in the jurisdiction of the court that condemned it as enemy property, and so I don’t know how they’re getting around that,” Lee said, adding that the boats would need to be docked in southern Texas if that is where the U.S. is going to open up prize court proceedings.
It is unclear what a prize law case will look like since no U.S. court has seen a prize case brought by the United States since the Spanish-American War, experts said. There is also uncertainty around the number of vessels that would be subject to the laws.
“I think we’re in a little bit of a make-it-up-as-we-go-along kind of situation here, partly because no one alive has been involved in a prize court in the United States,” Ralby said.

