The legal foundation for the Trump administration's seizure of oil tankers at sea is narrower than the policy ambition behind it - and may not hold up if Washington tries to expand the practice beyond vessels with clear ties to Iran.
Peter E. Harrell, a former senior director at the National Security Council and now a visiting scholar at Georgetown's Institute of International Economic Law, has raised the concern in a new Foreign Affairs essay, "Hvylya" reports.
American sanctions have traditionally operated on a "freezing" principle, Harrell explained: "sanctioned assets are frozen, but ownership does not transfer to the United States." A sanctioned payment routed through an American bank gets stopped, but Washington does not take possession of the money. Seizing a ship, by contrast, means the government physically takes the asset - a far more aggressive act that demands stronger legal justification.
For now, the Trump administration appears to be relying on provisions of U.S. law that allow seizure of money and resources linked to designated foreign terrorist organizations. Trump designated Iran's Islamic Revolutionary Guard Corps as a terrorist organization in 2019, and the administration has reportedly persuaded U.S. judges that at least several seized ships have ties to Iran. If it prevails in court, the administration likely plans to sell the tankers and their cargo.
The problem, Harrell argued, is scalability. If Washington wants to go after ships that lack clear links to Iran or other terrorist-supporting states, "it will need to find an alternative legal theory, either under domestic law or the laws of war, to take possession of them." Without that theory, the seizure campaign may remain limited to vessels the administration can plausibly connect to the IRGC.
The legal uncertainty matters beyond courtrooms. If other countries view the seizures as legally unfounded, they may feel more justified in retaliating with their own seizures of American cargo - a risk Harrell described as substantial and one Washington has not had to contemplate for decades. Also read how Gulf states began reassessing U.S. military bases as the Iran war shook trust in Washington.