Operation Epic Fury: Reports of the Death of International Law are Greatly Exaggerated

The recent U.S. and Israel military operations against Iran have prompted significant criticism from international lawyers, including on this site, that the strikes are contrary to international law. Operation Epic Fury, the title of the U.S. campaign, is just one of several recent challenges to legal orthodoxy concerning the exercise of legal control over State action. In the past year the international legal community has been confronted with the June 2025 U.S. – Israeli strikes against Iranian nuclear facilities, air defense systems, and senior leaders and scientists; the U.S. military operation in Venezuela to seize Nicolás Maduro; the ongoing attacks against drug cartel boats in the Caribbean and the East Pacific Ocean; and the recent U.S. threats to Greenland.

As Yuval Shany and Amichai Cohen have accurately and ominously stated, there is “a growing perception among policymakers that international law no longer offers a workable framework of norms and institutions for addressing the most serious problems of international peace and security.” This is occurring in a context where it is believed we may be witnessing the death of international law. However, as Mark Twain might put it, the reports of the death of international law are greatly exaggerated. That said, the legal community will have to reconsider how international law is interpreted and applied if that body of law is to remain relevant in the 21st Century.

There is certainly a disconnect between the views of many international lawyers and those of many State policy makers. While many legal commentaries have stridently opposed these recent U.S. actions, the reaction by States have been considerably more diverse. President Donald Trump’s designs on Greenland met with condemnation, although many States remained publicly silent. The United Kingdom, the Netherlands, and Colombia (see also Canada) were reported to have restricted intelligence sharing that might be used by the United States for strikes against drug cartels. Interestingly, the response to the Maduro seizure was more mixed with some U.S. Latin American allies supporting the move (e.g. Argentina, Peru Ecuador), while others responded “diplomatically, saying they’re monitoring the situation and urging respect for the rule of law. Others strongly condemned the U.S. actions, calling them “unacceptable. ”

[Editor’s note: see U.S. Allies and Adversaries’ Reactions to Operation Absolute Resolve to Capture Maduro]

The response to Operation Epic Fury has been especially equivocal with some States opposing the action (e.g. Russia, China, Spain, Italy, France, Switzerland) and others offering support (e.g. Canada, Australia, Ukraine, NATO Secretary General). Notably Canada expressed support for the goal of denuclearizing Iran, although Prime Minister Mark Carney subsequently called the operation “an example of the failure of the international order” involving action that is “inconsistent with international law.” Attempts have been made to distinguish between defensive versus offensive action. Following an attack on its base in Cyprus, the United Kingdom. changed its approach from relying on international law to reject support for U.S. military attacks on Iran to permitting their use of British bases to “facilitate specific and limited defensive action against missile facilities in Iran which were involved in launching strikes at regional allies.” Further, the United Kingdom. indicated it was going “to intercept drones or missiles targeting countries not previously involved in the conflict.”

This attempt to distinguish between offensive and defensive action gives new meaning to the term “nuance.” Canada and other States are similarly reported to be considering coming to the defense of Gulf States in response to Iranian missile and drone attacks. Adil Haque suggests the U.K. position attempts to achieve an impossible separation from unlawful U.S. offensive operations (see also Aurel Sari’s analysis of the U.K. “tightrope”) Suggesting there is a subtle distinction between offensive and defensive uses of force does not alter the fact that the United Kingdom will be engaged in an armed conflict with Iran at the same time as Israel and the United States. It seems only one small step removed from the action taken by the United Kingdom, the United States , and Jordan in coming to Israeli’s defense in October 2024 by shooting down missiles and drones fired by Iran. A position Jordan finds itself in once again in the recent hostilities.

So why the apparent disconnect between the certainty with which international law advocates condemn the strikes on Iran and the equivocal reaction by many States? The issue is whether orthodox legal interpretations provide the necessary clarity, or more significantly may be out of step with the reality facing States. I say this with an acknowledgement that some U.S. action can be readily viewed as breaching international law. As reflected in my and Geoffrey Corn’s analysis of the targeting of the drug boat cartels, international lawyers can be highly critical of the action undertaken by the United States. Further, I find myself in the situation where my 2016 book Fighting at the Legal Boundaries was relied on by the U.S. Justice Department Office of Legal Counsel (p. 5) for the proposition that the Maduro raid created an armed conflict. It did. However, there is much in the rest of that opinion which is unsupportable at law. The Maduro operation is a singular example of State aggression carried out under the guise of law enforcement.

Problematically, the Trump administration has been overtly dismissive of international law, and of its own civilian and military lawyers who have traditionally worked to ensure the United States operates within the bounds of international law. However, the negative perception of this administration should not brush all action as being outside recognized international norms. International law is not dead, and it continues to perform an essential role in establishing norms and restricting – and yes, at times justifying – State uses of force. In this regard the two Trump administrations have regularly relied on the language of international law and its norms (e.g. collective self-defense, armed attacks, necessity, proportionality) to explain and justify their actions (see here, here, and here).

Part of the problem faced by members of the legal community is that the certitude of their legal conclusions does not always match the complexity of the situations being assessed. Recently, Julian Ku argued: “International law governing the use of force has ossified into a formal binary. A strike is either lawful or unlawful. There is little space in the doctrine to distinguish among profoundly different uses of force.” The challenge for those criticizing Operation Epic Fury is that the ongoing hostilities with Iran are fundamentally different from a historical, factual and legal perspective than the invasion of Venezuelan territory and the drug boat strikes. Further, when confronted with State reactions that do not conform to their legal analysis it is not uncommon for some international lawyers to almost dismissively refer to State positions as being examples of realpolitik (i.e. practical determinations devoid of moral or ethical premises). However, the State responses might more often be properly characterized as grounded in realism (i.e. accepting and dealing with situations as they really are without being influenced by your emotions or false hopes).

The international legal community could benefit from reflecting on the degree to which its traditional interpretations of the law are out of step with the threats facing States and how States are responding to those threats. This is not the first time international law has been considered to be in crisis when confronted with the requirement to make potentially radical change in its interpretations of the law. Prior to 9/11, there was a widely held position that States could not exercise self-defense against non-State actors posing a transnational threat unless their actions could be attributed to a State. When faced with such a threat post 9/11, greater acceptance developed within the international community that such a threat could trigger the right of self-defense, with a growing number of States taking the view that defensive action could lawfully be undertaken where a State was unwilling or unable to deal with the non-State actor operating from their territory even though concerns remain concerning the elasticity of the right to self-defense. The right to take defensive action against non- State actors is recognized in the 2005 Chatham House Principles of International Law on the Use of Force by States in Self- Defence (Rule 6), the 2010 Leiden Policy Recommendations on Counter- Terrorism and International Law (para. 38) and the 2024, Rule 37)(this author was a participant). As David Kretzmer noted in a 2013 article (p. 273) the requirement that the actions of a non-State actor be attributed to a State to justify the use of extra-territorial forces “is no longer the majority view.”

The license for States to act in self-defense carries with it the potential for abuse. The response by the international legal community has largely been to try and limit abuse by significantly, and arguably overly, restricting State defensive action. This is done with narrow interpretations of the self-defense principles of necessity, imminence, proportionality and immediacy; by applying an elevated gravity threshold for determining the existence of an armed attack (Nicaragua, para. 247); and by individualizing threats rather than looking more broadly at a series of events to better contextualize the overall threat to State and international security.

What’s more, restrictionists may apply a tactical approach that focuses on individual attacks. They reject the idea that a series of strikes or an accumulation of events could justify the exercise of self-defense, or that the exercise of self-defense might not always progress along a linear trajectory. Overall, the goal of the restrictionist approach is understandable, but at times it is highly formalistic and reflective of the Cold War context in which it was created – an approach focused on the initial use of force between the major East and West protagonists. The approach has also proven inadequate in some security situations such as the protection of nationals. In the case of the 2001 evacuation of German nationals from Afghanistan, for example, the government suggested there may be a customary law exception to the U.N. Charter Article 2(4) prohibition on the use of force, an effort that might break out of the restrictionist mold.

Even more significantly, many restrictionists appear to maintain a strict separation of the law governing the right to act in self-defense from that governing the use of force once conflict begins. This does not account for situations like the Iran conflict where the States are involved in continuing hostilities, but there are pauses in the violence. For example, the hostilities between the parties in June 2025 were followed by an announcement of a ceasefire. However, as international lawyers know, a ceasefire does not terminate a conflict, it only pauses it. The Iranian armaments program, including the development of a nuclear capability, appears to have continued. President Trump referred to that program being restarted in his Feb. 25, 2026 address to Congress and stated Iran would never be permitted to have nuclear weapons. In that light, the 2026 Operation Epic Fury is best seen as a continuation of an already existing armed conflict with Iran. This means that the analysis of self-defense must be considered in the context of an ongoing state of war between the countries involved, and as it turns out more broadly within the region. Rather than focus on individual attacks, the law needs to be applied more realistically by considering the full scope of the hostilities.

Consider the length and breadth of the conflict between the United States and Iran and its proxies as the record presents a messier reality than simply looking at the attacks launched on Feb. 28, 2026. Starting with the 1979 seizure of the U.S. Embassy and consulate in Iran and subsequent aborted hostage rescue mission, there has been a litany of attacks against U.S. citizens, military personnel and interests. This includes the 1983 destruction of the Beirut Marine barracks and U.S. embassy by Hezbollah, the 1985 kidnapping, torture and murder of the C.I.A. station chief, the 1987 and 1988 hostilities concerning oil platforms in the Gulf, the tragic 1988 shootdown of an Iranian commercial airliner by the U S S Vincennes, and the 1996 Khobar Towers bombing in Saudi Arabia. Following the 2003 invasion, Iraqi Shiite militia were trained and equipped by Iran leading to an estimated 600 American casualties. There was also a 2011 Iranian plot to murder the Saudi ambassador on U.S. soil. The United States has also acted collectively with Israel against the threat posed by Iran and its proxies. It is reported to have included the 2008 killing of the Hezbollah terrorist leader, Imad Mughniyeh, in Syria, and the 2009 “Stuxnet” cyber-attack on the Iranian nuclear weapons program,

The conflict intensified in 2019 when Iran shot down an American drone and the U.S. carried out strikes and cyber-attacks against Iranian targets. Subsequently numerous attacks were carried out on U.S. bases by Iranian backed Iraqi militia that eventually killed an American contractor. The Iranian- backed militias threatened the U.S. embassy in Baghdad, and, on January 3, 2020, the U.S. carried out the targeted killing of Iranian Major-General Soleimani and the Shiite Iraqi leader, Abu Mahdi al-Muhandis. In 2022, US prosecutors charged an alleged Iranian agent for attempting to kill former National Security Advisor John Bolton, and former Secretary of State Mike Pompeo was also reportedly on the hit list. The hostilities between the United States and Iraqi militia continued over time but eventually lessened. As already noted in 2025 the United States became involved in defending Israel from Iranian attacks that occurred during hostilities flowing from the tragic attacks on Israel by Hamas in October 2023. In addition, the United States carried out over 800 strikes in Yemen against the Iranian backed Houthis who were seeking to disrupt international maritime shipping. Ultimately, in June 2025 the United States acted in collective self-defense with Israel attacking and significantly damaging Iran’s nuclear weapons program. Just this past week a Pakistani man was convicted in a New York court of planning in 2024 to work with the Iranian government to murder President Trump and other high-ranking officials (notably, the second such alleged Iranian plot to kill President Trump).

The United States has never lost the title of being the “Great Satan” with its ally, Israel, not only being called the “Little Satan”, but also continually being threatened with extinction by Iran. Shockingly this means Iran, a member nation of the U.N., is committed to destroying another recognized State. This puts Iran in company with Russia with its ongoing attempt to forcefully absorb Ukraine. These are true threats to the international rules based order. It is just one indication of what makes Iran’s potential possession of nuclear weapons and the means to deliver them (e.g. ballistic missiles) such a serious threat to international peace and security.

Looking at events since 2019 alone it is apparent the U.S. has been engaged in continuing hostilities involving Iran and its proxies, none of which have been brought to a formal conclusion. This raises the issue of the relationship between Iran and its proxies (e.g. Hezbollah, Hamas, the Houthis, the Iraqi Shiite militias). As I outlined in a 2022 article on the application of self-defense during this shadow conflict, it could be challenging to conclude that Iran exercises effective control over these groups. However, there are three other ways in which the United States may be involved in armed attacks and reciprocal acts of self-defense with Iran: by means of Iran’s “substantial involvement” with those groups (Nicaragua, para 195); by Iran’s exercise of “overall control” over those groups (Tadic, para 137), and as a result of the armed groups simply being allied essentially as co-belligerents with Iran in attaining a common goal. At a minimum, these, all represent the intimate connection between Iran and its proxies in a common cause that poses demonstrable national security threats to Israel, the United States and more widely in the region.

As Olivier Corten indicates (The Law Against War, p. 470), substantial involvement encompasses providing “massive support for armed bands operating from the territory of the State in question, without the State actually participating in the armed actions as such.” This clearly fits Iran’s relationship with those proxies thereby establishing their actions are attributable to that State for the purposes of self-defense. Notably, Israel relied on the “substantial involvement” criterion in its legal justification for carrying out Operation Rising Lion against Iran in 2025 flowing from the tragic Hamas attack of October 2023. The Israeli legal rationale underpinning the recent strikes is that the attacks are a continuation of an “already existing international armed conflict that Iran had sustained for years through direct and indirect armed attacks.” It is no question that if Israel had a right of self-defense to launch attacks against Iran in June 2025 and February 2026, the United States would have the concomitant legal prerogative to act in Israel’s collective self-defense upon the latter’s request.

Shany and Cohen have provocatively suggested that the failure of the international legal community to deal with Iran might lead to two possible outcomes. One being the (acknowledged highly problematic) adoption of an “illegal but legitimate” line of reasoning in justifying the use of force. The second being the acceptance of an (also acknowledged highly problematic) broadening of self-defence bordering on “self-preservation” reminiscent of the pre-Charter era. Perhaps not surprisingly this challenge to orthodoxy resulted in a swift reply from Tom Dannebaum and Rebecca Hamilton rejecting the idea “that international law must change to accommodate … States’ frustrations if a viable international legal order is to survive” and that “the inference of a general dissatisfaction with the substantive rules of the U.N. Charter is unfounded.”

In a staunch defence of the status quo, they argued if the United States and Israel considered their position acceptable to the international community they could have gone to the U.N. Security Council, relied on the Uniting for Peace Resolution, sought the support of the U.N. General Assembly, or used other unnamed international organizations. Acknowledging that the regime governing the resort to force is not perfect, their main suggested substantive change is seeking to reform the Security Council. What was not addressed has been the clear inability or unwillingness of the existing U.N. framework to deal with the threat posed by Iran, the historic failure to effect reform to the U.N. structure, and importantly that Israel and the United States. have been engaged in a continuing armed conflict/armed attacks with Iran.

Cognitive biases can help explain why “change is hard because people overestimate the value of what they have and underestimate the value of what they may gain by giving that up.” Yet, if the international legal community wants to effectively deal with security threats in the 21st Century, change is necessary, however difficult, to remain relevant. The change required need not be as radical as indicated by Shany and Cohen, or as ineffective in the short term as argued by Dannenbaum and Hamiliton. What is needed is interpretive change about how the use of force is regulated. It has already been suggested that the law governing self-defense and the conduct of hostilities should and can be applied simultaneously. An approach that restrictionist interpretations of international law have so far failed to apply. Yoram Dinstein’s more limited theory (War, Aggression and Self-Defence 6^th ed, paras. 473-47) requires reconciling the simultaneous application of the recourse to war rules and humanitarian law particularly in respect of the application of the proportionality of the State response. His theory suggests it can impact the geographical and temporal scope of a conflict involving more minor attacks (e.g. incidents “short of war”), although the hostilities with Iran appear to have moved beyond that threshold. Even when the conflict expands to “war” there is a requirement to make a force versus counter force proportionality assessment, albeit at the inception of the hostilities.

A second, overarching theory suggested in a 1989 article by Christopher Greenwood (pp. 273-88) and a book by Judith Gardam (Necessity, Proportionality and the Use of Force, pp. 156-57) contemplates the self-defense principles of necessity and proportionality applying throughout a conflict. However, as Greenwood acknowledges the more extensive the violence the less influence the self-defense principles will have such as in areas of its geographic scope. Even in that context, the violence must still be limited by humanitarian law rules governing the conduct of hostilities. Notably, Israel addressed the potential continuing application of the law governing the use of force at length in its 2025 Operation Rising Lion justification even though it did not believe it applied as a matter of law to the ongoing conflict (p. 20). That justification stated: “The scale and scope of Israel’s Operation were proportionate to what was required to neutralize the imminent and existential threat posed by the Iranian regime’s nuclear weapons program, as well as to the other imminent and actual Iranian attacks against Israel during the Operation. The Operation ceased once its objectives were achieved and a ceasefire was announced.”

Given the ongoing nature of the Iran hostilities and the international concern that they will expand in scope and intensity, it is the Greenwood-Gardam based overarching theory of the continuing application of the law governing the resort to the use of force throughout an international armed conflict that would likely attract the most support. It shifts the analysis away from the imminence of an individual tactical level attack in the context of an armed conflict where the threat has already been established to questions about whether the defensive response is necessary and proportionate. Rather than focus on individual attacks it also requires a holistic strategic assessment of the goals of the defending State. It is here where the justification for Operation Epic Fury may be most challenged due to the unclear and often changing rationale provided by the U.S. a dministration.

There are a number of issues that need to be addressed. For example, what changed from President Trump’s 2025 declaration that the nuclear threat had been “completely and totally obliterated” to a situation where a ceasefire was terminated? To what degree had the Iranian armaments program re started? As Shany and Cohen suggest, “the imminence of the nuclear threat … has diminished (although, obviously, both nuclear and ballistic threats did not disappear altogether and remain a serious problem).” If the situation changed sufficiently then attacks directed at removing Iran’s nuclear and ballistic missile threat would appear to be more consistent with the initially stated threat posed by Iran rather than seeking regime change or a complete surrender. If the strategic objectives have changed such that regime change or surrender is being considered, why is that necessary to achieve security, and what will be the proportionate means to achieve it?

Further, to what degree are U.S. strategic goals tied to its exercise of collective self-defense with Israel since that country is under a significantly greater threat from Iran? The situation facing Israel may justify a more ambitious defensive response. However, it is not clear that the strategic goals of the two countries are the same. For example, as Fareed Zakaria has noted while from a security perspective Israel might find a chaotic collapsed Iran acceptable, the United States may not due to the potential impact it could have on the region which depends upon stability and predictability “so that oil, goods, money and people can flow freely and easily through it.”

Linking the legality of State action to the strategic goals of an operation more directly aligns the law with issues that most concern States. Denuclearizing Iran is likely to more easily garner political support internationally, as well as being more readily justified at law. Not necessarily so with seeking the full unconditional surrender of Iran without an explanation of what comes after. It is one thing to remove an immediate threat, yet another if the result is greater regional and international instability. As General David Petraeus sagely said, “Tell me how this ends.” Adopting an overarching approach to the exercise of State self-defense more likely means the legal analysis and political assessments based in realism will be aligned toward seeking the same goal: limiting the conflict and its second-order impacts. International law is under duress, but it need not be in crisis. It has a meaningful role to play, but not one anchored in formal restrictionist Cold War thinking. I am sure some restrictionists will critique my analysis by claiming it is not grounded in orthodox interpretations of international law. I agree. Twenty-first Century threats require an application of the law based in realism, not aspiration.

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