The Iranian warship torpedoed by a U.S. submarine in the Indian Ocean this week had departed Indian waters just days earlier, completing a port visit and multinational naval exercise hosted by New Delhi. The incident has ignited political controversy in India and left the government of Prime Minister Narendra Modi without a public response.
Sri Lanka's navy recovered 87 bodies and rescued 32 survivors from the IRIS Dena as of Thursday, with around 10 sailors still unaccounted for. A second Iranian vessel entered Sri Lanka's exclusive economic zone in the aftermath of the sinking, though officials have not identified the ship or explained its presence.
India's Exercise, Iran's Ship
Exercise MILAN is India's flagship biennial multilateral naval drill, designed to foster maritime cooperation among participating nations. The 13th edition ran concurrently with the International Fleet Review 2026 in Visakhapatnam from Feb. 15-25, drawing representatives from 74 countries and 18 foreign warships.
Iranian Navy Rear Adm. Shahram Irani attended and held talks with India's chief of naval staff. Indian Defense Minister Rajnath Singh presided over the opening ceremony under the event's theme, "United Through Oceans."
The IRIS Dena represented Iran in both events. She sailed out of Visakhapatnam when MILAN concluded Feb. 25 and was heading home to Iran when a U.S. fast-attack submarine fired a single Mark 48 torpedo into her hull March 4, in international waters roughly 25 miles south of Sri Lanka.
The U.S. Navy sent no surface warship to MILAN. Its only official presence was a P-8A Poseidon maritime patrol aircraft from Patrol Squadron 4. The guided-missile destroyer USS Pinckney had been slated to attend but was diverted to Singapore on Feb. 15 before the exercise began, for reasons the Navy has not publicly disclosed.
Three days after MILAN ended, the U.S. and Israel launched Operation Epic Fury. The IRIS Dena was still in transit at the time.
Responses From Tehran and Washington
Iranian Foreign Minister Seyed Abbas Araghchi framed the sinking as an attack on a vessel that had been under Indian diplomatic protection.
"The U.S. has perpetrated an atrocity at sea, 2,000 miles away from Iran's shores," he wrote on social media. "Frigate Dena, a guest of India's Navy carrying almost 130 sailors, was struck in international waters without warning. Mark my words: The U.S. will come to bitterly regret the precedent it has set."
The Pentagon offered a different view. Gen. Dan Caine, chairman of the Joint Chiefs of Staff, described the strike at a Wednesday briefing as a demonstration of unmatched American military capability.
"To hunt, find and kill an out-of-area deployer is something that only the United States can do at this type of scale," Caine said.
U.S. officials have maintained throughout Operation Epic Fury that Iranian naval vessels operating in international waters remain valid military targets regardless of recent port calls.
The Debate in New Delhi
India's silence has drawn sharp criticism domestically, particularly from opposition politicians who argue the Modi government is abdicating its responsibilities as a self-described net security provider in the Indian Ocean.
Opposition leader Rahul Gandhi accused Modi of surrendering India's strategic independence at a critical moment.
"The conflict has reached our backyard, with an Iranian warship sunk in the Indian Ocean," Gandhi wrote. "Yet the Prime Minister has said nothing. At a moment like this, we need a steady hand at the wheel. Instead, India has a compromised PM who has surrendered our strategic autonomy."
Congress lawmaker Jairam Ramesh noted that Singh had personally inaugurated the exercise the IRIS Dena attended just days before her sinking.
"This U.S. action has enormous implications for India as well and it is shocking that there has been no official response to it till now," Ramesh wrote. "Never before has the Indian government looked so timid and fearful."
Criticism came from outside party politics as well. Former Indian Navy chief Arun Prakash said New Delhi should formally convey its "deep concern and displeasure" over a strike that unfolded in its maritime neighborhood.
Former diplomat Kanwal Sibal argued the values underpinning MILAN had been undermined and claimed that exercise protocol bars participating ships from carrying ammunition, which would have left the IRIS Dena unable to defend herself when struck. That claim has not been independently confirmed.
The Stakes for India
India has cultivated ties with both Washington and Tehran, and the sinking has exposed the difficulty of maintaining that balance. Indian officials have publicly noted that more than 40 percent of the country's oil imports transit the Strait of Hormuz, now an active combat zone.
India has also invested years in building MILAN into a cornerstone of its maritime diplomacy, presenting itself as a stabilizing presence in the Indian Ocean. The IRIS Dena's sinking days after departing that exercise puts both of those positions under pressure New Delhi has yet to publicly acknowledge.
The IRIS Dena's two Moudge-class sister ships, Jamaran and Sahand, were destroyed earlier in Operation Epic Fury. U.S. officials say American forces have sunk more than 20 Iranian naval vessels since the campaign began, effectively dismantling Iran's conventional surface fleet.
Now, with the war expanding into the Indian Ocean and Iranian vessels allegedly still in the area, neighboring nations are watching nervously.
