The conflict between the United States and Iran took a dramatic turn on 4 March 2026 when a US submarine reportedly sank an Iranian warship near the coast of Sri Lanka. The attack marks a historic moment in modern naval warfare, as US officials described it as the first enemy ship sunk by a torpedo since World War II.
According to US Defence Secretary Pete Hegseth, the Iranian vessel believed it was safe in international waters before it was suddenly hit by a torpedo launched from an American submarine.
US Confirms Torpedo Attack
Speaking to reporters, Pete Hegseth confirmed that a US submarine carried out the strike in the Indian Ocean near Sri Lanka.
He described the attack as a “quiet death”, referring to the stealth capabilities of submarines.
According to Hegseth:
“An American submarine sunk an Iranian warship that thought it was safe in international waters. Instead, it was sunk by a torpedo.”
Military analysts say this incident highlights the increasing role of underwater warfare and stealth technology in modern conflicts.
Iranian Warship IRIS Dena Sinks
The ship that sank was the IRIS Dena, a Moudge-class frigate belonging to the Iranian Navy.
The warship had recently participated in the MILAN 2026 multinational naval exercise held in Visakhapatnam, India, before heading back toward Iran.
According to reports:
- Around 180 sailors were onboard
- Nearly 150 crew members are currently missing
- Several sailors are confirmed dead
- Sri Lankan authorities are conducting search operations
The sinking occurred in the Indian Ocean region near Sri Lanka, prompting immediate rescue efforts.
Sri Lankan Navy Launches Rescue Operation
Sri Lankan officials confirmed that distress signals were received from the Iranian ship shortly before it went down.
Sri Lankan Navy spokesman Buddhika Sampath said rescue teams were sent immediately.
He stated:
“We have found a few bodies from the area where the ship had gone down.”
Sri Lanka deployed:
- Naval ships
- Air force aircraft
- Search and rescue teams
The operation is still ongoing as authorities try to locate missing sailors.
Part of the Wider US–Iran War
The incident comes amid an escalating conflict between the United States, Israel, and Iran.
According to the Pentagon, one of the strategic objectives of the ongoing war is to neutralize Iran’s naval capabilities.
Reports also suggest that:
- US and Israeli military officials started planning the first phase of attacks three weeks earlier.
- Coordination between the Pentagon and Israeli military intensified after Israel decided to launch strikes against Iran.
Military experts believe targeting Iran’s navy could significantly weaken its ability to control key shipping routes in the Indian Ocean and Persian Gulf.
Why This Attack Is Historically Important
Defence analysts say the sinking of IRIS Dena is significant for several reasons:
- First torpedo sinking since World War II
- Demonstrates the power of modern submarine warfare
- Signals a new phase of escalation in the US-Iran conflict
- Raises concerns about maritime security in the Indian Ocean
Submarines are considered one of the most dangerous weapons in naval warfare because they can attack without being detected.
Global Concerns Rising
The attack has triggered concerns among several countries in the region, including India, Sri Lanka, and Gulf nations, due to the possibility of further military escalation.
Experts warn that if the conflict expands, it could disrupt:
- Global shipping routes
- Oil transportation through strategic sea lanes
- Maritime security in the Indian Ocean
This could also affect global trade and energy markets.
Conclusion
The sinking of the Iranian warship IRIS Dena by a US submarine marks a significant moment in modern warfare. As tensions between the United States and Iran continue to rise, the incident highlights how naval power and underwater warfare are becoming central to global military strategy.
With rescue operations still ongoing near Sri Lanka and hundreds of sailors feared missing, the situation remains tense. The coming days may determine whether this incident escalates into a wider regional conflict.
