The Iranian warship IRIS Dena, which had recently concluded its participation in the Indian Navy’s multilateral maritime exercise MILAN 2026, was sunk by a US Navy submarine in the Indian Ocean. The incident occurred near the maritime zone of Sri Lanka as the vessel was navigating its return route to Iran. According to official reports from the region, at least 87 Iranian personnel have been confirmed dead, while approximately 60 others remain missing. The Sri Lankan Navy managed to rescue 32 survivors from the water. This unprecedented attack has sent shockwaves through the international maritime community, marking a significant escalation in regional tensions.
Scale and Participation of Exercise MILAN 2026
The 13th edition of the MILAN exercise, hosted by the Indian Navy, took place from February 21 to February 25 off the coast of Visakhapatnam. According to the Indian Navy, this edition was the largest to date, featuring participation from 74 nations. For the first time, countries such as Germany, the Philippines, and the UAE participated with their military assets. The exercise involved approximately 42 warships and 29 military aircraft from across the globe. Among the 18 foreign warships present was the Iranian vessel IRIS Dena. The exercise aimed to strengthen maritime cooperation and foster interoperability among friendly naval forces in the Indo-Pacific region.
Nature of the Attack and Historical Context
The attack on IRIS Dena was carried out by a US Navy submarine using torpedoes, according to statements from the US Department of Defense, while the warship reportedly sank within minutes of being struck. US defense officials noted that this incident represents the first time since World War II that a warship has been sunk by a torpedo attack in a combat-like engagement. The vessel was carrying an estimated 180 personnel at the time of the incident. This development is being viewed by military historians and strategists not merely as a naval clash but as a historic shift in maritime warfare dynamics in the 21st century.
Details of Search and Rescue Operations
Following the attack, the Sri Lankan Navy launched an immediate search and rescue operation in the affected area of the Indian Ocean. Official figures confirm that 32 Iranian sailors were pulled from the sea and provided with emergency medical care. However, the death toll has reached 87, with a significant number of personnel still unaccounted for. Rescue teams are continuing their efforts to locate the missing 60 individuals, though the depth of the water and sea conditions pose challenges. The loss of life has been described by regional authorities as a major maritime tragedy, prompting concerns over the safety of naval personnel in international waters.
International Maritime Law and Jurisdiction
The sinking of IRIS Dena has raised complex questions regarding international maritime law. Under established naval protocols, a warship remains under the sovereign jurisdiction of its home nation, while while a host nation like India is responsible for the safety of visiting vessels within its territorial waters, this responsibility ends once the ship enters the high seas. According to international maritime experts, the security of a vessel in international waters is the sole responsibility of the flag state's navy. Since the incident occurred in international waters near Sri Lanka, it falls outside the direct security mandate of the host nation of the MILAN exercise.
Iranian Response and Regional Geopolitical Tensions
The Iranian government has issued a stern statement holding the United States directly responsible for the destruction of IRIS Dena, while tehran has characterized the ship as a guest of the Indian Navy at the time of the exercise and warned of potential retaliatory measures. This incident is widely interpreted as an extension of the ongoing geopolitical friction between Iran and the United States in the Middle East, now manifesting in the Indian Ocean. While India has expressed natural concern over the loss of life, diplomatic observers emphasize that the event took place in international waters as part of a broader conflict theatre that exists independently of the multilateral exercise.