By Kamran Adil and Warda Kamran Adil
INTRODUCTION
Emerging developments in international relations can be analysed through different lenses. These may include, inter alia, military and strategic considerations, international legal frameworks, economic consequences, religious dimensions, and cultural perspectives. The purpose of this brief analysis is to take stock of the legal issues that should be considered before forming views on the ongoing US-Iran War. The issues may be discussed under the following thematic areas:
In the context of shifting geo-political dynamics, the first and foundational question concerns the very existence of the international legal order based on rules or the applicability of international law. This question is not new. The proponents of the view that international law lacks effective enforceability often cite Professor Hans Kelsen, who, in Principles of International Law (1959), questioned the effectiveness of international law due to the absence of centralised enforcement mechanisms. The nub of his argument was that, unlike national legal systems, international law lacks a centralised enforcement mechanism. Despite such scholarly critique, international law has evolved and expanded over the last seven decades and turned into a multilateral system that is now under strain. Indeed, international law predates the twentieth century and existed in various forms long before the modern international system emerged. The most ancient part of international law is the law of war that is now commonly referred to as International Humanitarian Law (IHL). There are, in fact, two streams of international law that must be noted: jus ad bellum (law of war) and jus in bello (law in war). These two aspects of the US-Iran War are discussed separately here:
Jus ad bellum (law of war) deals with the objectives of war and its casus belli (reason for going to war). The US is leading the war, and Israel has joined it in its military campaign. The casus belli of both is divergent. While the US President Trump has been offering ‘destruction’ of nuclear capabilities along with ‘regime change’ as his objectives of war, Israel has called it a ‘pre-emptive’ strike against Iran in its self-defence. The reasoning advanced by both does not find any support in the extant international law material that is primarily stated in the UN Charter. In fact, their actions blatantly violate Article 2(4) of the UN Charter and do not fit into the concept of collective self-defence under Article 51 as these actions were not authorized by the United Nations Security Council (UNSC). On the other hand, Iran’s actions taken in self-defence fully find support from the customary as well as treaty-based international law. The act of attacking a country is such a serious matter that the Rome Statute of the International Criminal Court, 1998, criminalizes the “crime of aggression” (unfortunately, neither the US nor Israel are parties to the Statute). Thus, at least normatively, this law shows that the unjustified casus belli by the US and Israel are illegitimate. It was precisely for this reason, at least initially, that the UK has not joined the ‘aggression’, and it is hoped that much of the world would weigh this point before queuing behind the US. In this context, the US–Iran war is predominantly being viewed as “unjust”, inter alia, on the following grounds:
- Two states possessing nuclear weapons (i.e., the United States and Israel) attacked a non-nuclear state (i.e., Iran); this apparent imbalance speaks volumes about the engineered nature of the war;
- The fact that Israel attacked Iran’s nuclear sites in 2025 (along with the United States) shows that this is the second instance of “aggression” against Iran within two years, and any claim of “pre-emptive” self-defence is therefore contrived;
- “Regime change” is squarely against Article 2(4) of the UN Charter, as it amounts to interference in the political independence and sovereignty of a member state of the United Nations. The assertion by the United States that it is attempting to “liberate” the Iranian people through regime change by the use of force (without authorization of the United Nations Security Council) clearly violates customary international law and militates against the spirit of international relations reflected in United Nations General Assembly Resolution 3314 (1974).
Jus in bello (law in war) is generally best understood through two major bodies of law: the Geneva Law (the law of protection in war) and the Hague Law (the law of conduct of hostilities as well as the means and methods of warfare). The Geneva Law (GL) is based on customary international law, the four Geneva Conventions of 1949, and two Additional Protocols of 1977. Similarly, the Hague Law (HL) finds its legal foundations in customary international law as well as the Hague Conventions of 1899 and 1907. The specific treaties on different material like anti-personnel mines (the Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction, 1997), cluster munition (Convention on Cluster Munitions, 2008), chemical weapons (Chemical Weapons Convention, 1997), biological weapons (the Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on their Destruction, 1975), etc., may also be conceptually considered to be part of HL. Questions regarding disarmament are often discussed within the broader framework of IHL. Since the adoption of the Additional Protocols to the Geneva Conventions in 1977, the treaty law governing the conduct of hostilities has evolved considerably, alongside developments in customary international law. The principles of distinction (between the civilian and military objectives), proportionality (ensuring that incidental civilian harm is not excessive in relation to the anticipated military advantage), and necessity form part of every professional military training and are often disseminated by the International Committee of the Red Cross. The targeting of a girls’ school in which over a hundred girls were killed in Iran resulted in serious violations of the IHL by Israel. In a similar vein, many civilian sites were hit by the US and Israel showing their lack of respect for the IHL, or for international customary law. These expressions of illegitimacy will not deter the US, or its partner in crime, Israel, from their wrongful acts; however, on a moral and global level, underlining these instances may serve in the future to assess who disrupted the global order and brought destruction to humanity.
The concept of “neutrality” has two connotations under IHL: first, that a “neutral” state ought to remain impartial towards the parties to an international armed conflict (war); and second, that “humanitarian organizations”, such as the International Committee of the Red Cross (ICRC), should be treated as “neutral” by the parties to an armed conflict so that they can carry out humanitarian activities. In the context of the US–Iran war, the question of the “neutrality” of the Gulf and Arab states has come under discussion. It may be noted that the discipline of International Relations (IR) has long acknowledged the concept of “neutrality” under customary international law; it was later codified in treaty law, particularly in the Hague Convention (V) Respecting the Rights and Duties of Neutral Powers and Persons in Case of War on Land, 1907 (Hague Convention V). As an example from the last century, during the initial phase of the First World War, the United States attempted to remain “neutral”. However, prominent scholars such as Quincy Wright argued that there is no such thing as “absolute neutrality” and that, after the adoption of the UN Charter, states could only exercise a form of “qualified neutrality”. In any case, an objective assessment of the Gulf and Arab states as “neutral” is not straightforward. Many of these states host United States military bases or permit the use of their territory for military purposes, and this fact complicates their status as “neutral states”. Iran has therefore taken aim at some of the US military bases located in these “neutral” states, inviting discussion about the rights of such states to respond to these strikes. This intricate factual matrix also raises legal questions for Pakistan, which has entered into a mutual defence agreement with Saudi Arabia, itself often described as a “neutral” state in the present conflict.
- BLOCKADE OF THE STRAIT OF HORMUZ
In response to the attack on it by the United States, Iran has established a blockade of the Strait of Hormuz. This act by Iran has disrupted nearly 20% of the global supply of oil, raising international prices of petroleum products. Owing to its global impact, the legal aspects of this blockade have come under discussion. The United Nations Convention on the Law of the Sea (UNCLOS) deals with this matter. However, neither Iran nor the United States is a party to the Convention: Iran signed the treaty in 1982 but has not ratified it, while the United States has also not ratified the Convention. Nevertheless, many of the relevant rules contained in UNCLOS are widely regarded as reflecting customary international law. Part III of UNCLOS provides that straits used for international navigation (connecting Exclusive Economic Zones or the high seas) should allow “transit passage” to all vessels (Articles 37 to 44 of UNCLOS). While international humanitarian law (IHL) requires belligerent states to avoid unnecessary interference with international waterways, the deployment and movement of warships in and around the Strait of Hormuz could transform parts of the strait into a military objective, potentially allowing Iran to justify certain actions under IHL. Iran’s claim to treat the strait as a military objective has further been reinforced by the recent action of the United States in torpedoing an Iranian vessel near Sri Lanka.
- KILLING OF AYATOLLAH ALI KHAMENEI
The head of state enjoys certain immunities under international law, including those recognized in the Vienna Convention on Diplomatic Relations, 1961. A question arises whether such immunity continues to apply during an international armed conflict. In this regard, Article 48 of Additional Protocol I of 1977 to the Geneva Conventions obliges parties to an armed conflict to distinguish between civilian objects and military objectives and to ensure that civilians are protected.
CONCLUDING REMARKS
Commenting on the US–Iran war, The Economist, in its latest issue published on 7 March 2026, noted that the United States has waged a war “without a strategy.” The war is now over a week old, and it remains uncertain which party will ultimately win it. However, there is a growing acknowledgment that international security and peace have already lost, and that the effectiveness of the UN system has been severely undermined.
