Law Without Teeth

Introduction

In 1832, in his work "The Province of Jurisprudence Determined," John Austin made this observation; it reflects a long-standing sceptical belief about the nature and effectiveness of international law. International Law is not like the domestic legal frameworks functioning under a sovereign authority, which is capable of enforcing rules and imposing sanctions; this law, on the other hand, operates differently in the case of sovereign states, which is based on a decentralised system. This raises an important question, i.e. can international law truly function as law when there is no central authority capable of enforcing it?

The controversy surrounding the effectiveness of international law has once again gained momentum with the occurrence of recent international incidents. Sinking of the Iranian naval frigate IRIS Dena by a United States submarine in the Indian Ocean on 4 March 2026, at a time when the vessel was returning from a multilateral naval exercise hosted by India. The skirmish, which took place in international waters near the Sri Lankan coast, resulted in the death of dozens of Iranian sailors and has also led to widespread criticism across the world, with many raising questions about the legality of such use of force under the existing international legal framework. 

The seriousness of this issue is increased by the fact that, as reported, the vessel was on its way back, returning from a naval exercise and was not engaged in any active hostilities at the time it was struck. Such circumstances bring forth important questions regarding the applicability of principles such as self-defence, the rules of engagement, and the legal justification for targeting naval vessels that are outside an active combat zone, along with the broader issue of freedom of navigation.

Factual background of the US–Iran naval incident

A major naval skirmish occurred in the Indian Ocean region on 4 March 2026 when a submarine belonging to the United States Navy torpedoed and sank the Iranian naval frigate IRIS Dena off the southern coast of Sri Lanka, approximately 400 nautical miles from the Indian Coastline. The attack took place in international waters near the Sri Lankan port city of Galle and resulted in serious casualties amongst the crew of the vessel. Sri Lankan authorities have since recovered at least eighty-seven bodies and rescued more than thirty sailors from the wreckage following emergency rescue operations. 

The frigate was returning to its home port after successful participation in an international fleet review hosted by India, named Ex-MILAN. This exercise was intended to enhance maritime cooperation in the region, with several foreign naval forces participating. 

The said skirmish happened in the midst of increasing tensions between the Islamic Republic of Iran and the United States as part of a larger regional conflict. This regional conflict had already involved air and missile strikes across multiple areas in the Middle East in the past. 

The incident immediately gained international criticism as the Iranian frigate was reportedly returning from a friendly naval exercise and was not actively engaged in hostilities at the time of the strike. Critics and analysts questioned whether the ship posed an imminent threat that could justify the use of lethal force under international law. 

International legal framework regulating the use of force at sea.

International law governing the use of force is derived from the United Nations Charter. The Charter had sought to establish a system of collective security aimed at preventing unilateral military action. One of the main foundations of this framework is contained in Article 2(4) of the Charter, according to which an obligation on all the member states is imposed, which mandates them to refrain from the threat or use of force against the territorial integrity or political independence of any state.

However, the ban on using force is not universal. In the case of an armed attack, the inherent right to individual or collective self-defence is preserved by Article 51of the Charter, which acknowledges a limited exemption, i.e. cases of Necessity and proportionality.

Additionally, UNCLOS (United Nations Convention on the Law of the Sea) regulates the international relations at sea. It governs the jurisdiction, navigation, and activities carried out across the world's oceans. To properly examine the incidents like sinking of IRIS Dena this relationship between laws becomes significant. Whether the actions taken in this incident are consistent with recognized principles of international law is assessed through an understanding of these legal principles.

Rules of engagement and the principles of Necessity and proportionality

International law only establishes general principles regulating the use of force, whereas the operational aspects and conduct of military forces are guided by the Rules of Engagement (ROE). These rules act as standing directions issued by military commands which define the conditions and limitations under which lethal force may be used during military operations.

The United States military follows the Standing Rules of Engagement (SROE) issued by the Joint Chiefs of Staff Department of Defence, which explicitly state that:

"U.S. forces will comply with the Law of Armed Conflict during military operations involving armed conflict, no matter how the conflict may be characterised under international law, and will comply with the principles and spirit of the Law of Armed Conflict during all other operations." 

The legality of the use of force is determined on the basis of the identification of hostile intent.

They define hostile intent as:

“The threat of imminent use of force against the United States, U.S. forces, or other designated persons or property.”

But, in the present case, reports suggest that the vessel had been returning from a multinational naval exercise hosted by India and was sailing through international waters near Sri Lanka at the time of the attack. The ship was reportedly not engaged in active combat operations and had not demonstrated any immediate hostile action toward the United States naval forces operating in the region. Whether the threshold of hostile intent necessary to justify the use of force had been met or not is a question that these circumstances have raised.

Based on this are the principles of Necessity and proportionality, which form the foundation of the rule under Article 51 of the UN Charter. The rule of Necessity says that a force may only be used when it is the only reasonable means available against an imminent threat. 

Similarly, the Rule of Proportionality says that the amount of force used has to be limited, i.e. a force necessary to neutralise the apparent threat and not more than that. Using a torpedo to strike a naval vessel, especially one that is not engaged in any hostility at that time, raises questions regarding the proportionality of the act.

Also, the presence of trainee officers on board the said vessel increases the complexity of the legal justification, since it is evidence suggesting that the ship may not have been in a combat-ready capacity.

Conclusion

The attack on IRIS Dena is not a case of an isolated naval skirmish happening on earth, but it brings to light broader challenges regarding the conduct of states under international law and their regulation. International law has not been an underdeveloped area of law; rather, it contains a comprehensive framework designed to regulate such situations. The central problem is that it is a silent spectator, and its true effectiveness is ultimately determined by the willingness of states to adhere to these norms. Further, the absence of a central authority for enforcement and accountability has increased this non-adherence.

It was almost two centuries ago when John Austin raised doubts regarding international law and whether it could truly function as law in the absence of an enforcing sovereign; the jurisprudence given by him is still relevant, as the challenges he raised are still visible in the international relations of today. Despite huge developments in modern-day international relations and law, the conflicts between legal principles and political realities continue to shape the way international law operates. 

The way out is through a reform that could address this persistent gap. Adoption of automatic jurisdiction for the International Court of Justice (ICJ) in cases involving the use of force at sea is one such reform. This mechanism would require the states to submit disputes arising from naval encounters directly to the ICJ, without the need for a separate consent in each case. This enlargement of jurisdiction would enhance accountability and provide an avenue for impartial adjudication, which would make it a credible and predictable process. While the path to such a reform would be complex and would demand significant political will from the international community, planting the seed for such change can help transform Austin's enduring critique into a constructive agenda for strengthening the effectiveness of international law.