(NEW YORK) — The sinking of an Iranian warship Tuesday by a U.S. submarine thousands of miles from the war zone in international waters raises questions about whether the attack was legal under the rules of war.
Military law experts said the Iranian ship, which was in the Indian Ocean in international waters off Sri Lanka, would have been a lawful target had the U.S. declared war. The fact that it hasn’t done so makes the issue a murky one.
Iranian Foreign Minister Abbas Araghchi called the attack an “atrocity.”
“The U.S. will come to bitterly regret precedent it has set,” he said.
Experts say the incident highlights the reason that a declaration of war by Congress is needed for the growing conflict, which has involved more than 12 countries, as Iran continues launching drones and missiles at countries beyond the Persian Gulf region.
The House of Representatives on Thursday voted against a war powers resolution. Similar legislation failed Wednesday in the Senate. Both votes largely followed party lines.
The submarine strike in international waters “underscores why Congress should have approved this in the first place,” said Retired Lt. Col. Rachel VanLandingham, a former judge advocate general in the U.S. Air Force, “because this is a war [in which they’re] going to go after the Iranian Navy,” even when naval assets are outside the Middle East.
“The Iranian Navy is not small, right? It could be in places like outside of Sri Lanka and international water.”
Under the laws of armed conflict, were the U.S. and Iran in a declared war, the warship would represent a lawful target, former U.S. government lawyers told ABC News.
The issue with the submarine’s attacking the warship in international waters, VanLandingham said, was “political” in nature and not legal.
“When you’re going to have such global implications — that’s one of the reasons the founding fathers said Congress gets to decide wars of choice,” she said.
Brian Finucane, who was attorney-adviser at the State Department from 2011 to 2021, also said the submarine attack would have been lawful if the conflict was authorized.
According to Finucane, the U.S. would have an obligation under the Geneva Conventions to conduct search and rescue operations for survivors of the sinking.
A source familiar with Tuesday’s operation said the submarine took measures to support life-saving efforts before and after the ship sank in line with international law.
The military’s compliance with that international law was called into question when a second strike on an alleged drug boat killed survivors in international waters in the Caribbean Sea in September.
“The fundamental legal problems under both U.S. and international law” of the submarine engagement, Finucane said, “relate to the underlying use of force in this war against Iran.”
Authorization by Congress for the war is required by law because the U.S. offensive against Iran is not a response to an imminent threat, experts said.
President Donald Trump and his administration have said Iran posed such a threat. Secretary Marco Rubio said the threat became more imminent because Israel planned to strike Iran and Iran would retailiate against Israel and the U.S.
While the president has called the conflict a “war,” senior officials in his administration — and top leadership in Congress — have refrained from using the word.
Speaker of the House Mike Johnson said Wednesday the U.S. “is not at war now.”
The Pentagon’s top policy official, asked whether the U.S. was at war with Iran in a congressional hearing Thursday, would not use the term.
“I think we’re in a military action at this point,” said Undersecretary of Defense for Policy Elbridge Colby. “I will leave to Congress and lawyers from the administration, et cetera, to determine.”
Ambiguity about the conflict’s label from across the government comes as Pentagon officials say the conflict will only “accelerate” in intensity — and potentially grow in scope.
The U.S. military mission is in a “throttle-up” posture, said Defense Secretary Pete Hegseth, who would not confine the campaign to a time limit.
“The only limits we have in this is President Trump’s desire to achieve specific effects on behalf of the American people,” Hegseth said.
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