Naval Legitimacy In The Modern Era: From The Graf Spee To the IRIS Dena – OpEd |
The destruction of the Iranian frigate IRIS Dena by a United States submarine on 4th March 2026, has reignited a century-old debate regarding the legitimacy of naval strikes in international waters. By examining the Dena incident alongside the historic sinkings of the German ‘pocket battleship’ Admiral Graf Spee (1939) and the Argentine cruiser General Belgrano (1982), a complex picture emerges of how strategic necessity, rules of engagement (ROE), and political optics define the legitimacy of a maritime sinking.
The IRIS Dena, a Moudge-class frigate of Iran’s Southern Fleet, was struck by a single Mark-48 torpedo launched by the Los Angeles Class Submarine, USS Charlotte approximately 20 nautical miles off the coast of Sri Lanka. US Defense Secretary Pete Hegseth characterized the event as a “quiet death” for a vessel that erroneously thought it was safe in international waters.
The legitimacy of this strike is grounded in the existence of an active shooting war between the US-Israel and Iran that began on 28 February 2026. Under maritime law during such hostilities, any ship belonging to a belligerent nation is considered fair game. However, the sinking remains controversial because the Dena was returning from Exercise MILAN 2026, a multinational peacetime naval gathering hosted by India. Iran has labeled the strike an “atrocity at sea,” arguing the vessel was a diplomatic guest and was struck without warning in international waters.
The 1982 sinking of the General Belgrano provides the closest modern parallel to the Dena. Like the Dena, the Belgrano was torpedoed by a submarine (HMS Conqueror) while outside a designated restricted area, the Total Exclusion Zone (TEZ).
The British government, in particular, the Secretary of Defense, Michael Hesiltine, MP, justified the action as legitimate self-defense, citing intelligence that the Argentine navy was planning a coordinated pincer movement to attack the British task force. They argued that a warning was issued on 23rd April 1982, explicitly stating that any Argentine vessel posing a threat would face an “appropriate response,” regardless of its location. Critics, however, viewed the sinking as illegitimate and politically motivated to undermine Peruvian peace proposals, especially as later reports confirmed the Belgrano had reversed course and was sailing away from the task force at the time of the attack.
Scuttling vs. Surprise Strikes
The fate of the Admiral Graf Spee in 1939 offers a different perspective on naval legitimacy. Unlike the sudden torpedo strikes on the Dena and Belgrano, the Graf Spee was scuttled by its own crew.
The ship’s legitimacy as a target was never questioned; it was an active commerce raider that had sunk nine Allied merchant ships. After sustaining damage during the Battle of the River Plate, Captain Hans Langsdorff sought refuge in the neutral port of Montevideo. Faced with the choice of sailing to certain destruction against a falsely reported massive British fleet or internment, Langsdorff scuttled the ship to save his crew’s lives. This end was self-inflicted and dictated by international neutrality laws rather than a surprise strike.
Comparative Legitimacy and Strategic Precedent
Several themes emerge when comparing these three naval milestones. In both the Belgrano and Dena cases, the legitimacy of the strike was defended through intelligence assessments of the target’s threat level assessments that were subsequently challenged as being unnecessary or politically timed. The Belgrano sinking forced a shift in ROE that allowed for attacks outside formal exclusion zones. This set a precedent that arguably paved the way for the US to target the Dena in international waters far from the primary conflict zone. For the IRIS Dena, the debate centers on the moral responsibility of the host nation (India) versus the legal right of a belligerent (the US) to strike an enemy during wartime.
What requires closer examination is the legitimacy of the sinking of the Dena in light of the fact that it was not actively participating in operations against the US & Israel Vs Iran war. Whilst the sinking of the Belgrano was justified in view of the active threat it posed to Britain’s naval assets in the Falklands, the sinking of the Dena feeds directly into the US determination to neutralize Iranian assets and bring about an ‘unconditional surrender’. In words of Hegseth,
“Our rules of engagement are bold, precise and designed to unleash American power, not shackle it. This was never meant to be a fair fight, and it is not a fair fight. We are punching them while they’re down, which is exactly how it should be.”
Legal scholars may argue that the laws of war were designed for the very purpose of checking the use or potential abuses of military force. There are two questions which must now be addressed. What will be the fate of the rescued Iranian sailors currently residing in Sri Lanka? Additionally, Sri Lanka has provided refuge to the Iranian naval auxiliary vessel, IRIS Bushehr. Given that it has been the intention of the US up until now to locate and neutralize all Iranian ground, air and naval assets, it may prove challenging for them to target the IRIS Bushehr and will test whether the US is willing to violate the sovereignty of Sri Lanka.
Dr. Jacob Thomas-Llewellyn is Assistant Professor in the Defense and Security Program at Rabdan Academy. He was previously a Resident Researcher with the Centre for Army Leadership (CAL) at the Royal Military Academy Sandhurst and most recently was a lecturer in the Department of International Relations at the University of Reading, where he taught across undergraduate and postgraduate levels and lectured on International Relations Theory, Strategic Studies and Warfare. His PhD was a study of British civil-military relations during the Second World War, with a specific focus on industrial mobilization and the planning, fabrication and delivery of the artificial Mulberry Harbours and the Pipeline Under the Ocean (PLUTO). He is a recipient of the Peter Campbell Prize, awarded by the University of Reading and an Associate Fellow of the Royal Historical Society. Alongside his academic duties, he is an avid book collector and has a particular interest in 17th century military manuals. He is also an experienced fly fisherman and military wargamer.
Ms. Sinduja Umandi W. Jayaratne is currently a Research Fellow – Lecturer at Rabdan Security and Defence Institute (RSDI) at Rabdan Academy (UAE). She is an accomplished Sri Lankan scholar and a practitioner specializing in Irregular Threats (Information Operations, Terrorism, Violent Extremism and Proxies), Intelligence, National Security and Resilience, with nearly fifteen years of experience across academia, intelligence analysis, humanitarian affairs, and strategic advisory roles. She also serves on the International Advisory Board of the Research Institute for European and American Studies (RIEAS), Greece. Prior joining RSDI she was a Senior Researcher at the Bandaranaike Centre for International Studies (BCIS), Sri Lanka and a Lecturer in the Department of Strategic Studies in General Sir John Kotelawala Defence University. She also served as a Research Fellow in Michael J. Morell Center for Intelligence and Security Studies at The University of Akron, USA. Ms. Jayaratne is an alumna of Near East South Asia Center for Strategic Studies (NESA) in National Defence University, Washington D.C.