On April 21, 2026, Reed Rubinstein, the Legal Adviser at the U.S. Department of State, issued the Trump administration’s lengthiest explanation of its views on the worldwide legislation justification for the U.S. warfare towards Iran, Operation Epic Fury. Both the timing and presentation of this assertion had been uncommon when it comes to the U.S. authorities’s previous practices. The assertion arrived nearly two months after the president began the warfare. To its credit score, the assertion was offered as an opinion of the Legal Adviser, posted publicly on the State Department’s web site. Publicly articulating the U.S. authorities’s worldwide authorized arguments on extremely contested points is a optimistic growth that must be embraced. Unfortunately, the substance of this new justification is each legally unpersuasive and analytically confused.
The core authorized arguments of the Rubinstein assertion are that:
“Epic Fury is only the latest round of an ongoing international armed conflict with Iran. …[T]he United States is engaged in this conflict at the request of and in the collective self-defense of its Israeli ally, as well as in the exercise of the United States’ own inherent right of self-defense.”
But the backside line stays that the United States has failed to point out that both Israel or the United States suffered an armed assault by Iran, which is important to justify the use of power in self-defense. The Rubinstein assertion’s repeated declare of an ongoing armed battle is a real pink herring. As with the March tenth Article 51 letter to the UN Security Council, this U.S. assertion fails to ascertain that President Donald Trump’s warfare of alternative is something aside from what it seems—a manifestly unlawful use of power in violation of the UN Charter. The Trump administration wanted to carry one thing else to the dialogue to beat that conclusion. The assertion reveals there’s nothing there.
Although this assertion gives transparency – and could function a rebuttal to latest critiques (reminiscent of a letter from international law experts and my very own prior analysis – this faulty and overly permissive justification dangers additional eroding authorized constraints on the use of power.
Legal Background
Under worldwide (and domestic) legislation, the UN Charter sharply restricts the use of power by States. Article 2(4) of the treaty prohibits “the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.”
Article 51 of the Charter in flip specifies, in related half, that
Nothing in the current Charter shall impair the inherent proper of particular person or collective self-defence if an armed assault happens towards a Member of the United Nations, till the Security Council has taken measures needed to keep up worldwide peace and safety. Measures taken by Members in the train of this proper of self-defence shall be instantly reported to the Security Council
Thus, however the prohibition on the use of power imposed by Article 2(4), the forcible measures by States in particular person or “collective self-defense” (performing to defend one other State) are permissible and should be reported to the UN Security Council.
Critically, the textual content of the Article 51 requires an “armed attack” as a prerequisite for the use of power in self-defense. Beyond that, the United States and different States have endorsed the idea of anticipatory self-defense in response to an imminent menace of armed assault as customary worldwide legislation. While some have advocated for a proper of States to make use of power in preventative self-defense towards extra inchoate threats, according to the weight of State opinio juris and knowledgeable opinion, the U.S. authorities has by no means adopted this idea of preventative self-defense.
To the opposite, in 1981, in response to a preventative Israeli assault on an Iraqi nuclear facility at Osirak, the United States joined a unanimous UN Security Council resolution in “strongly condemn[ing] the military attack by Israel in clear violation of the Charter of the United Nations .” In the view of the United States, Israel’s actions violated Article 2(4) as a result of the
“absence of any evidence that Iraq had launched or was planning to launch an attack that could justify Israel’s use of force. … [T]he presence in a State of the military capacity to injure or even to destroy another State cannot itself be considered a sufficient basis for the defensive use of force.”
Further, the possession of nuclear weapons (which, to be clear, Iran didn’t and doesn’t possess) by itself wouldn’t even represent an illegal menace of the use of power, a lot much less entitle different States to actions in self-defense. The United States took the position earlier than the International Court of Justice (ICJ) in the Nuclear Weapons case. The United States submitted: “With respect to a threat to use nuclear weapons in a particular case, such a threat may or may not be lawful – just as a threat to use conventional weapons may or may not be lawful – depending on the circumstances in question.” Consistent with this view, in its advisory opinion (para 47-48), the ICJ declined to endorse the argument that possession of nuclear weapons by itself constituted an illegal menace of the use of power. More broadly, the mere possession of weapons, standard or in any other case, doesn’t justify the resort to armed power absent an imminent menace of armed assault.
Also of potential relevance in the case of Iran, in some circumstances a State’s assist to a non-State actor participating in an armed assault offers rise to a proper of self-defense towards the supporting State (along with the non-State actor). As articulated by the ICJ in the Paramilitary Activities case, the proper of self-defense could also be engaged by “‘the sending by or on behalf of a State of armed bands, groups, irregulars or mercenaries, which carry out acts of armed force against another State of such gravity as to amount to’ (inter alia) an actual armed attack conducted by regular forces, ‘or its substantial involvement therein.’”
As Michael Schmitt and Alexander Hernandez have famous, in the context of Iran’s assist for regional armed teams, a key challenge is not only whether or not a State “sends” armed bands however whether or not State assist quantities to “substantial involvement” in armed assaults by the armed teams. In the view of the ICJ, the mere arming and equipping of an armed group, or the provision of logistical or different assist, doesn’t quantity to an armed assault giving rise to the proper to make use of of power in response.
Any use of power in the train of self-defense can be topic to the customary worldwide legislation necessities of necessity and proportionality. For the use of power in self-defense to be lawful, it should be needed. As defined by the State Department’s Legal Adviser in 2016, the “international law of self-defense requires that such uses of force be necessary to address the threat giving rise to the right to use force in the first place.” As articulated in the Caroline correspondence between the United States and the United Kingdom, the “necessity of self-defence” requires “no choice of means.” Thus, to ensure that the use of power to be needed, peaceable options to addressing the supposed menace—together with diplomacy—should be unavailable or exhausted.
“Oceania had always been at war with Eastasia”—The Ongoing Armed Conflict Theory
The Rubinstein assertion asserts that Operation Epic Fury was launched in the context of ongoing worldwide armed conflicts between the United States and Israel with Iran. “The operations recommenced in late February were part of an armed conflict with Iran that has been ongoing for years and, at the least, since June 2025.” This ongoing armed battle authorized idea echoes the Trump administration’s revisionist historic narrative that the United States has been at warfare with Iran for 47 years, since the 1979 hostage disaster—an Orwellian rewriting of the previous that will have come as a shock to many Americans.
There are layers of issues with the administration’s ongoing armed battle idea.
In the first place, the declare of an ongoing armed battle is immediately at odds with the Trump administration’s personal prior statements. The administration repeatedly acknowledged that the June 2025 warfare with Iran is over and ended, opposite to the assertion’s assertion that the “parties did not make unilateral declarations concerning an end to hostilities.” For instance, in June 2025 President Trump himself declared the 12 Day War with Iran to have come to an “Official END.” And in October 2025, the State Department proclaimed on social media that Trump, the “PRESIDENT OF PEACE” had ended “8 wars in 8 months” and listed the “Iran and Israel” as one in every of the conflicts supposedly ended.
Second, the assertion’s central thesis continues to conflate the physique of guidelines figuring out when States are in an “armed conflict” for functions of making use of the Geneva Conventions (jus in bello) with the physique of guidelines for when a State could resort to power in self-defense (jus advert bellum). This downside is apparent to worldwide legal professionals (see Adil Haque’s discussion of “Armed Attack and Armed Conflict”). A telltale signal of the error is the assertion’s reliance on commentaries by the International Committee of the Red Cross for guidelines governing the finish of armed battle – regardless of the well-known indisputable fact that the ICRC avoids any evaluation of jus advert bellum as outdoors its group’s mandate. What’s extra, the authorized threshold for a world armed battle is exceedingly low: the ICRC commentaries themselves note, counting on U.S. apply, {that a} state of armed battle could also be created “after the capture of just one member of their armed forces” (emphasis added). It is thus nonsensical to say there isn’t a have to assess jus advert bellum in an ongoing armed battle (which can be triggered by a single ongoing detention), and but the assertion makes that declare all through.
Third, the Rubinstein assertion doesn’t specify with precision when both Israel’s or the United States’ supposedly ongoing armed conflicts with Iran started. Instead, with respect to each international locations, the assertion hedges by claiming that hostilities have been ongoing since at “least” sure dates (with alternate dates given in numerous elements of the assertion). Such ambiguity obscures the challenge of how these armed conflicts started and whether or not it was in truth Iran that launched the predicate armed assault—or whether or not Israel and the United States attacked first. By means of comparability, Russia could also be engaged in an ongoing armed battle with Ukraine however that doesn’t alter whether or not Russia’s assault upon Ukraine was unlawful in the first place. Nor would anybody even recommend Russia’s invasion of Ukraine in February 2022 was not a violation of the UN Charter as a result of Russia and Ukraine had been already in an armed battle following Russia’s invasion of Crimea and occupation by proxies of elements of Eastern Ukraine. It can be a laughable argument.
Fourth and relatedly, by invoking a supposed ongoing armed battle, the Rubinstein assertion seeks to skirt the jus advert bellum necessities of necessity and proportionality. The assertion asserts that “[a]s a matter of international law, there is no requirement to continually reassess jus ad bellum principles of necessity and proportionality in the context of an ongoing armed conflict.” It cites as an alternative a previous speech by then-State Department Legal Adviser Brian Egan, which makes a really completely different declare (particularly, that “once a State has lawfully resorted to force in self-defense against a particular armed group following an actual or imminent armed attack by that group, it is not necessary as a matter of international law to reassess whether an armed attack is imminent prior to every subsequent action taken against that group, provided that hostilities have not ended.”) (emphasis added). The assertion cites no different authority for this proposition relating to necessity and proportionality — a place which is inconsistent with worldwide legislation, together with as interpreted by the United States.
As the U.S. authorities defined in a 2016 framework produced after in depth interagency session by profession subject material consultants, “the use of force in self-defense in an ongoing armed conflict is limited by respect for States’ sovereignty and the considerations discussed above, including the customary international law requirements of necessity and proportionality when force could implicate the rights of other States.” In different phrases, States do have to reassess the jus advert bellum necessities of necessity and proportionality even in an ongoing armed battle. And as defined under, the Trump administration has failed to ascertain that the use of army power is important.
Finally, if the United States had been engaged in an ongoing armed battle with Iran since a minimum of June 2025 (as the assertion claims), then the Trump administration can be utilizing army power in violation not solely of the U.S. Constitution, which explicitly grants Congress the authority to determine when the nation goes to warfare, but in addition of the 1973 War Powers Resolution. The War Power Resolution (amongst different issues) imposes a 60-day time deadline for the elimination of U.S. armed forces from hostilities not approved by Congress. President Trump’s assaults towards Iran in 2025 and 2026 lacked congressional authorization and the 60-day clock for this supposedly ongoing armed battle would have lengthy expired.
No Predicate Armed Attacks towards Israel or the United States
The Rubinstein assertion’s ongoing worldwide armed battle idea due to this fact doesn’t obviate the jus advert bellum requirement of a previous armed assault or menace of an imminent armed assault for the train of lawful self protection. But the assertion additionally fails to ascertain that particular armed assaults present the predicates for both the train of particular person or collective self protection.
The authorized justification (accurately) states that “[a]ny serious legal assessment of U.S. combat activities must be anchored in the relevant material facts.” Yet, the assertion’s factual narrative is imprecise, omits crucial data, and is inconsistent with prior claims by the first and second Trump administrations. Moreover, the justification devotes appreciable house to a list of legally extraneous particulars of Iran’s rhetoric, ideology, and dangerous acts, together with with respect to its assist for non-state actors reminiscent of Hizballah, Hamas, the Houthis, and paramilitaries. Without establishing that these info bear on the train of particular person or collective self protection, the factual recitation reads as an airing of grievances somewhat than substantiation for rigorous authorized arguments.
With respect to armed assaults towards Israel, the assertion appears to recommend that Hamas’ atrocities of October seventh, together with Iran’s personal drone and missile assaults of April and October 2024 could present the predicates for the use of power towards Iran. There are a number of holes in any such idea.
In phrases of Hamas’ assault of October seventh, the assertion doesn’t clarify how that assault constitutes an assault by Iran below worldwide legislation. As for Iran’s barrages towards Israel in 2024, each adopted assaults by Israel on Iran. In April 2024, Israel carried out a deadly assault towards Iranian officers in an Iranian authorities facility in Damascus, Syria. As for Iran’s October fusillade towards Israel, Tehran justified it by reference to previous Israeli assaults inside Iran towards a Hamas official in Tehran and an Iranian basic in Lebanon.
Regarding assaults on the United States, the assertion recites a litany of assaults on U.S. personnel and armed forces in the Middle East since 1979. But aside from the sacking of the U.S. Embassy in Tehran and taking of U.S. diplomats as hostages, it fails to specify how these assaults are imputable to Iran in order to present rise to a proper of self protection towards Iran. (Notably absent from this listing of misdeeds is President Trump’s allegation of Iranian accountability for the assault on the USS Cole.)
The Rubinstein assertion identifies no assaults by Iran towards Israel or the United States since the finish of the 12 day warfare in June 2025. Nor, opposite to different rhetoric by the administration, does the assertion depend on a idea that Iran posed an imminent menace of an armed assault. (The abandonment of this imminent menace argument follows the same development in Trump’s first time period of shifting and inconsistent justifications for the Soleimani strike.)
No Necessity
I wrote in March with respect to the Trump administration’s earlier justification of Operation Epic Fury in its Article 51 letter to the United Nations:
The basic downside with any try to justify Operation Epic Fury on the foundation of self-defense is that the U.S. assault was pointless. Far from being a warfare of necessity, the Iran War is a warfare of alternative. And it was Trump’s alternative.
The Rubinstein assertion does nothing to change this evaluation.
In addition to failing to particularly establish the armed assaults that might give rise to a proper of self protection, the assertion doesn’t set up that the use of army power was needed as a matter of jus advert bellum—that the United States had exhausted all peaceable means to deal with no matter menace Iran posed.
The selective historical past offered in the assertion omits that the United States had efficiently employed diplomacy to tightly constrain Iran’s nuclear program, topic to worldwide verification—till President Trump withdrew from the nuclear deal often called the Joint Comprehensive Plan of Action (JCPOA) in 2018. Moreover, it isn’t believable for the administration to argue it had exhausted diplomacy with Iran in both 2025 or 2026. The Trump administration didn’t mount a critical diplomatic effort remotely on par with that which the Obama administration used to barter the JCPOA or the interim deal that preceded it. The administration’s 2025 negotiations with Iran had been terminated not as a result of they had been futile, however as a result of Israel’s shock assault on Iran in the midst of the talks. Similarly, somewhat than the February 2026 negotiations having reached a lifeless finish, in response to the Omani mediators talking shortly earlier than the U.S. assault on Iran, negotiations had been as a result of proceed the following week with technical discussions.
More basically, these U.S. negotiations with Iran weren’t geared toward stopping an armed assault or imminent menace of armed assault. Even if they’d failed after in depth good religion efforts, the lack of ability to succeed in a diplomatic association passable to the United States (or Israel) on Iran’s nuclear program doesn’t give rise to a proper of self protection towards Iran absent an precise or imminent armed assault.
Unfortunately, it’s clear that the United States attacked Iran not due to the necessity of self protection, diplomacy having been exhausted, however judging from his personal repeated statements, as a result of President Trump sought to do a “Venezuela” in Iran. Emboldened by the tactical success of the decapitation raid into Caracas, Trump hoped for one more brief and candy army spectacle that decapitated the regime, leading to a brand new extra pliant chief taking the helm. It seems, after all, that Iran isn’t Venezuela.
A Standard to be Met, for Critical Reasons
As defined in the opening phrases of the UN Charter, the “Peoples of the United Nations [agreed to the Charter] to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind.”
Yet like all legal guidelines, the UN Charter and its prohibition on the use of power isn’t self implementing. The treaty due to this fact requires human beings—U.S. authorities officers, together with the President of the United States and his advisors—to faithfully execute its provisions. The principal and very important goal of the Charter—avoiding the ruinous bloodshed and destruction of warfare—will depend on the senior authorities legal professionals advising Trump and his Cabinet to deal with the legislation as a regular to be met even when their coverage counterparts are urgent for a selected final result.
As with the U.S. Constitution, the UN Charter sharply limits recourse to power for excellent causes. We are at present witnessing the penalties of the failure of the President’s advisors and senior most legal professionals to adequately convey these rationales—hundreds of lifeless (together with U.S. servicemembers), thousands and thousands displaced, international financial ache , a significant waterway obstructed, and a U.S. President flailing to extricate himself from a large number of his personal making.
FEATURED IMAGE: The U.S. Department of State in Washington DC. (Photo by Mark Wilson/Getty Images)
