Galle coast is seen after a submarine attack on the Iranian military ship, Iris DENA, off Sri Lanka on Wednesday.Thilina Kaluthotage/Reuters
Last month, as Washington and Tehran were locked in tense negotiations ostensibly aimed at avoiding all-out conflict, an Iranian warship travelled to India to join vessels from dozens of other countries for a multilateral exercise reaffirming freedom of navigation and maritime law.
By the time that warship, the IRIS Dena, left India this week however, the world had shifted: The U.S. and Israel were bombarding Iran, and the ship’s crew had little idea of what state their country would be in when they returned. They had even less idea they were being stalked by a U.S. submarine, which torpedoed the ship after it entered international waters, killing at least 84 people on board.
The sinking of the Dena in the Indian Ocean, far from the main theatre of the U.S.-Iran war, has raised major concerns about a further expansion of the rapidly escalating conflict, and questions about India’s supposed position as “guardian” of the vast waters as a UN-recognized “zone of peace.”
U.S. submarine sinks Iranian warship off Sri Lanka with torpedo, Hegseth says
“India has projected itself as the net security provider in the Indian Ocean,” said Praveen Donthi, a senior analyst with the International Crisis Group. “But this has exposed its weaknesses when it comes to controlling its own maritime neighbourhood.”
New Delhi has yet to publicly address the sinking of the Dena, which Iranian Foreign Minister Abbas Araghchi described as “an atrocity at sea, 2,000 miles away from Iran’s shores.” The ship, he noted, had been a “guest of India’s navy.”
A U.S. submarine sank an Iranian warship off the southern coast of Sri Lanka, U.S. Defense Secretary Pete Hegseth said on Wednesday.
Reuters
Amit Malviya, a senior figure with India’s ruling Bharatiya Janata Party, said it was “illogical and misleading” to suggest India bore any responsibility for the Dena, noting the sinking took place “well beyond India’s territorial waters and outside its maritime jurisdiction.”
“Attempts to drag India into this episode ignore the basic principles of maritime jurisdiction and appear driven more by speculation and political narrative than by facts,” he wrote on social media.
Anil Jai Singh, a retired commodore with the Indian Navy, agreed India did not have any responsibility to protect the Dena, regardless of why the ship was originally in the region.
“Purely from a navy perspective, once these exercises are over, everyone goes on to their missions and tasks. The ship travelled through international waters. U.S. submarines are present in the Indian Ocean, there is nothing secret about that,” he said. “The Iranians knew there was tension brewing by the time their ship had sailed, they should have been very alert or asked for refuge.”
A second Iranian vessel, IRINS Bushehr, has taken shelter in Sri Lanka, Sri Lankan President Anura Kumara Dissanayake said Thursday. Colombo has strongly objected to the attack against the Dena, which while in international waters, was within the exclusive economic zone of Sri Lanka.
“Our seas and skies can’t be used by another nation for their own gain or to harm another nation,” Mr. Dissanayake said. “Our actions since the beginning of the incident have been in line with that stance.”

An injured Iranian sailor receives treatment at the Karapitiya hospital in Galle after his frigate sank off Sri Lanka's coast.ISHARA S. KODIKARA/AFP/Getty Images
Some in India have expressed frustration New Delhi hasn’t taken a more forceful stance, with former foreign secretary Kanwal Sibal saying India bore a moral responsibility for the Dena, regardless of the specificities of maritime law.
“The U.S. has ignored India’s sensitivities as the ship was in these waters because of India’s invitation,” he wrote on social media.
Chulanee Attanayake, a researcher in maritime security at Swinburne University of Technology in Melbourne, said the silence from India was “deafening.”
“The Indian Ocean as a zone of peace has been a concept championed by India in the past,” Prof. Attanayake said. “This is the first time an external regional conflict has expanded into these waters, a moment when India should have and could have provided leadership in terms of security.”
Whether India was informed in advance or is choosing not to complain, this is another shift away from New Delhi’s position of “strategic autonomy” and toward firmer alignment with the U.S., she added, noting Indian Prime Minister Narendra Modi visited Israel just days before the initial strikes against Iran, as part of efforts to smooth over relations with U.S. President Donald Trump.
Mr. Donthi, the Crisis Group analyst, said the sinking of the Dena “is a big litmus test for India’s strategic autonomy and may have already ended any posturing towards that because of India’s apparent helplessness.”
The incident was reminiscent, he added, of how the U.S. “has taken liberties” with Pakistan in the past, conducting drone strikes in Pakistan and along the country’s border with Afghanistan without informing or consulting Islamabad.
Increasing the bad optics for New Delhi, a day after the sinking of the Dena, the U.S. granted India a 30-day waiver to buy sanctioned Russian oil to offset a drop in supply as a result of fighting in the Middle East. But what could have been a win for Mr. Modi has quickly become another attack line for his critics.
“The US proclamation to ‘allow’ and grant us ‘permission’ to buy Russian oil, as a ‘waiver for 30-days’ clearly demonstrates Modi Govt is continuously ceding diplomatic space,” Mallikarjun Kharge, president of India’s opposition Congress party, wrote on social media. “From trade to oil, from data to India’s long-term relationships with friendly countries, Modi ji surrendered it all.”
With reports from Neha Bhatt in New Delhi