Did US violate India's sovereignty as it torpedo Iranian warship Iris Dena in Indian Ocean? Maritime rule explained

Iris Dena visited India between Feb 17 and Feb 25 for the International Fleet Review 2026 and MILAN 2026 organised by the Indian Navy. India has also invited the US navy to participate in the event but America was represented by its officers only as no warships turned for the IFR, mainly due to preparations for the Iran war.

The US-Iran war has reached India’s backyard as the US Navy submarine torpedoed an Iranian ship near Sri Lanka, killing 87 people aboard, including sailors. The Sri Lankan Navy on Wednesday rescued 30 sailors from the Iranian naval ship "IRIS Dena", which was in distress with around 180 sailors onboard. United States Secretary of War Pete Hegseth on Wednesday confirmed that a US submarine had sunk the Iranian warship "IRIS Dena" with a torpedo hit.

"Yesterday, in the Indian Ocean, an American submarine sank an Iranian warship that thought it was safe in international waters. Instead, it was sunk by a torpedo. Quiet death. The first sinking of an enemy ship by a torpedo since World War II. Like in that war, back when we were still the War Department, we are fighting to win," Hegseth said.

Iris Dena visited India between Feb 17 and Feb 25 for the International Fleet Review 2026 and MILAN 2026 organised by the Indian Navy. India has also invited the US navy to participate in the event but America was represented by its officers only as no warships turned for the IFR, mainly due to preparations for the Iran war.

Attack Raises Questions

However, the attack has raised questions in India as well as in Sri Lanka over the alleged violation of the international maritime rules. Iranian diplomats in Colombo on Wednesday sought clues over the cause of the sinking off the Sri Lankan coast. Meanwhile, critics in India termed it a violation of India’s maritime might as the warship had visited Visakhapatnam for the naval exercise. 

Defence Expert Dr. Brahma Chellaney wrote on X, "By sinking a vessel returning from an Indian-hosted multilateral exercise, Washington effectively turned India’s maritime neighbourhood into a war zone, raising uncomfortable questions about India’s authority in its own backyard. In diplomatic terms, the strike violated the unwritten code of naval hospitality. Attacking a ship immediately after it leaves a host’s waters is widely seen as a slight to that host. The message to participating navies is stark: attending India’s exercises may not guarantee safety once they sail away."

What are international rules?

Under the United Nations Convention on the Law of the Sea (UNCLOS), a coastal country has full sovereignty over waters up to 12 nautical miles (about 22.2 km) from its baseline (usually the low-water line along the coast). Then comes the Contiguous Zone that spreads from 12–24 nm for limited enforcement (customs, immigration, security). 

Violation of India’s sovereignty?

The Iranian naval ship IRIS Dena was hit and sunk on 4 March 2026 in the Indian Ocean near Galle, Sri Lanka. About 40 nautical miles south of Galle on Sri Lanka’s southern coast. The approx distance of the Iris Dena hit from India could be around ~440–450 km or ~240 nautical miles. Thus, this is in the international waters for India and not even into India's exclusive economic zone up to 200 nm. 

So, until this is a threat to India, New Delhi has nothing to do with it as per international rules. Thus, it doesn’t violate India’s sovereignty.