Experts: US torpedo strike on Iranian warship did not violate international law

A U.S. submarine’s torpedo attack that killed at least 87 people aboard the Iranian warship IRIS Dena did not violate international or American military law, legal experts said. The strike took place in international waters in the Indian Ocean near Sri Lanka, as part of the broader U.S.-Israeli military operation against Iran, and hit a lawful military target, experts said — though what happened in the attack’s immediate aftermath raises a separate and still-unresolved legal question.

Thirty-two Iranian sailors were rescued after the attack. While experts broadly agreed the strike itself was lawful, they said U.S. forces may face scrutiny over whether they took sufficient steps to assist survivors — an obligation international humanitarian law and Pentagon rules both impose.

WASHINGTON — The Iranian warship IRIS Dena had just participated in naval exercises hosted by India and was heading home through international waters near Sri Lanka when a U.S. submarine’s torpedo struck it. At least 87 people died. Thirty-two Iranian sailors were rescued.

Legal experts said the attack was a lawful act of war. Whether the U.S. did enough to help those survivors reach safety is a different question — and one that remains open.

The strike itself

“Targeting a military vessel is not a war crime,” said Marko Milanovic, a professor of international law at the University of Reading in Britain. Milanovic described the Dena as “a clear military target,” adding that the ship’s distance from active combat and its participation in joint exercises were irrelevant to the legal analysis.

On the broader operation, however, Milanovic drew a sharper line. The attacks on Iran overall, he said, amount to “a clear violation of the UN charter” — a concern distinct from the individual strike.

Rachel VanLandingham, a professor at Southwestern Law School and a retired U.S. Air Force lieutenant colonel who served as a judge advocate general, agreed that neither the ship’s location nor its activities at the time shielded it from lawful attack.

“It doesn’t matter that it wasn’t firing at the time,” VanLandingham said. “It matters that it can be used to fire at American military assets.”

The aftermath

What transpired after the torpedo struck is a separate matter under international law, experts said.

International humanitarian law requires that attacking forces take “all possible measures” to help search for and collect anyone wounded or shipwrecked. The Defense Department’s Law of War Manual imposes the same obligation on U.S. forces, while acknowledging that “practical limitations” — including the cramped quarters of a submarine — may require alerting other ships, aircraft, or coastal authorities to the location of possible survivors rather than taking them aboard.

A U.S. official, speaking on condition of anonymity to discuss matters not authorized for release, confirmed that following the strike the United States contacted Sri Lankan authorities and provided the ship’s location for search and rescue efforts.

Sri Lanka’s foreign minister, Vijitha Herath, told Parliament that Sri Lanka’s navy received a distress signal from the stricken vessel and dispatched ships and planes on a rescue mission. By the time those forces arrived, the Dena had gone under.

“Only some oil patches and life rafts,” said navy spokesman Commander Buddhika Sampath. “We found people floating on the water.”

Calls for explanation

Brian Finucane, who served in the State Department’s Office of the Legal Adviser for a decade, said the legality of the strike is only the beginning of the analysis.

“The attack may not violate the law of war, but that’s only the start of the analysis,” Finucane said. “What happens after the attack is another matter.”

Without more information, Finucane said, “it’s hard to evaluate whether there were possible measures they could have taken. But at a minimum, they should be explaining this.”

Eugene R. Fidell, who teaches military law at Yale Law School, said a complete picture of the aftermath may be slow to emerge.

“It may be a long time before we have a full account of who did what and when in the aftermath of the attack,” Fidell said. He said that if the U.S. alerted coastal authorities, “they did right to do so” — but cautioned that difficult questions remain about whether rescuers were close enough to the scene in time to matter.

“So until we get more clarity, granular clarity, I think it’s premature to make any judgments,” Fidell said.