Stefan Messingschlager Download PDF Apr 16 2026 The widening U.S.-Israeli conflict with Iran is usually narrated as a Middle Eastern crisis.
That is true, but strategically incomplete.
Since the 28 February 2026 strikes on Iran and the wider conflict that followed, European governments have tried to distinguish non-participation, defensive assistance, and offensive enablement, while Asian governments have had to reckon with disrupted shipping, energy risk, and the possibility that American attention and assets could be drawn away from the Indo-Pacific.
The most revealing theatre of the war is therefore not only the Gulf.
It is also the wider political space in which states decide whether international law still constrains allies as well as adversaries.
That question matters well beyond Iran.
Any future crisis over Taiwan, the South China Sea, or coercion against a treaty ally will require more than U.S.
military power.
It will require a diplomatic coalition willing to name aggression publicly, align sanctions, absorb economic costs, and defend a common legal vocabulary.
The strategic issue, then, is not moral consistency in the abstract.
It is coalition-organising power: the ability to persuade other states that the standards invoked against rivals also bind ones own side.
Iran is a hard case, which is precisely why it clarifies the issue.
Tehran remainsrepressive at home, deeply troubling on the nuclear file, and violent through regional partners and proxies.
TheIAEA safeguards report of 27 February 2026recorded grave and unresolved proliferation concerns, while also noting continued diplomatic engagement and serious verification gaps.
Hard cases are where legal restraint matters most.
If force becomes acceptable whenever the target is odious enough, law stops operating as restraint and becomes a vocabulary of selective exemption.
My claim is not that legality overrides strategy.
It is that legality is itself part of strategy.
In a more plural order, partners are less likely to align durably behind states that present Charter limits as binding for adversaries but elastic for allies.
The Iran war is therefore a Middle Eastern conflict with Indo-Pacific consequences.
This is why the Iran case reaches far beyond the usual debate about Western hypocrisy.
Hypocrisy is a moral description.
Strategy requires a different register.
The relevant question is whether selective legality raises the diplomatic, fiscal, and domestic-political costs of future alignment for third states.
In a system where many partners are neither dependants nor neutrals but selective co-producers of order, that cost matters enormously.
Law as Strategic Capital This is why legality should be understood as strategic capital rather than ethical afterthought.Thomas Francks classic account of legitimacy in the international system,Ian Hurds work on legitimacy and authority, and Hurds later reflections oninternational legalismpoint toward the same reality: rules matter not only because they can be enforced, but because actors still feel compelled to justify themselves in legal terms.
In world politics, law is part of how coalitions are assembled, contested, and sustained.
That insight also sits close toJohn Ikenberrys account of liberal internationalismand order-building andAmitav Acharyas account of a more multiplex post-American order.
If order is less hierarchical and consent matters more, then reciprocity matters more too.
A state that wants others to share costs in a future Asian crisis must show that the rules it invokes are not merely discretionary instruments.
For that reason, the relevant benchmark in the Iran case should not be the infinitely elastic slogan of a rules-based order.
Recent work by theBritish Institute of International and Comparative Law,Malcolm Jorgensen, andMarc Trachtenbergshows why the phrase can blur the line between binding law and looser political preference.
In this case the relevant standard is theUN Charter.
Once the issue is framed that way, the strategic stakes become clearer.
Liberal democracies do not defend an order simply by wielding superior force.
They defend it by persuading others that force is exercised under shared restraints.
If those restraints are seen as optional whenever close partners act, then legal language becomes less persuasive when later deployed against Russia, China, or any other challenger.
The point is less moralistic than it may sound.
Legal argument is one of the arenas in which authority itself is contested.
States can live with disagreement over policy.
They are less willing to absorb serious costs for a coalition if they suspect that its legal vocabulary is reciprocal only when convenient.
Selective legality therefore corrodes not merely reputation, but the practical willingness of others to align.
From Charter Restraint to Preventive War The legal baseline is not obscure.Article 2(4)of the Charter prohibits the threat or use of force against the territorial integrity or political independence of states, andArticle 51preserves self-defence only under narrow conditions.
TheNicaragua judgmentremains central because it resists the idea that a generally dangerous adversary supplies a standing warrant for force.
There is of course a long-running debate over anticipatory self-defence.
But even narrower accounts of that doctrine still insist on imminence, necessity, and proportionality, as bothrecent legal analysisand the classic doctrinal literature onarmed attack and Article 51make clear.
Anticipatory self-defence is still about an immediate and unavoidable attack, not a broad licence to strike because another state may later become more dangerous or less deterable.
Once that temporal limit dissolves, prevention begins to masquerade as pre-emption.
The chronology matters.
TheIAEA safeguards reportdid not describe a benign nuclear file.
It underscored serious proliferation concern, recalled that Iran had accumulated440.9 kilograms enriched up to 60 percent, and stressed that the Agency lacked access sufficient to verify current inventories at affected facilities.
But the same report also recordedongoing U.S.-Iran negotiations on 17 and 26 February, and Rafael Grossi told the Board of Governors on2 Marchthat diplomacy and negotiations remained the only way to secure long-term assurance that Iran would not acquire nuclear weapons.
That combination is precisely why the case is hard: the threat was real, but diplomacy had not plainly run its course.
Necessity is therefore as important as imminence.
On demanding Charter readings, force becomes lawful only when peaceful alternatives are unavailable or exhausted.
Even on broader accounts of anticipatory self-defence, the core intuition is the same: the attack feared must be sufficiently immediate that delay would forfeit the right of defence.Brian Finucanes analysis of the U.S.
Article 51 letterandMarc Wellers argumentconverge here.
The law does not ask whether another state is gravely threatening in a general sense.
It asks whether resort to force has become unavoidable now.
Article 51 letter to the Security Councilinvoked self-defence to protect U.S.
forces, regional allies, and freedom of navigation.
Yet the letter also thickened the claim of present necessity by invoking a long history of Iranian hostility.
AsFinucane notes, that move turns a catalogue of past conduct into a continuing entitlement to use force.
The difficulty is doctrinal and strategic at once: once decades of enmity can substitute for imminence, the exception starts to swallow the rule.
The broader reaction from legal experts is important because it shows that the objection is neither fringe nor anti-Western.
Apublic letter signed by more than one hundred scholars and practitionerswarned against the unequal application of international law and against aid or assistance to internationally wrongful conduct.UN experts speaking through OHCHRlikewise insisted on de-escalation, accountability, and non-selective legal scrutiny.
One need not endorse every line of these interventions to see the central point: the better view is that the opening resort to force was not convincingly covered by the Charter.
None of this romanticises Tehran.
Irans own conduct, including attacks on civilians, maritime threats, and regional strikes, raises grave questions under both jus ad bellum and international humanitarian law.
But later unlawfulness by Iran cannot retroactively legalise the initial resort to force.
Once strategic intelligibility is allowed to displace legal sufficiency, law stops constraining war and starts explaining it away.
Europes Uneasy Conditionality European reactions reveal the difficulty with unusual clarity.
In their28 February statement, the E3 stressed non-participation, regional stability, and renewed negotiations.
Their1 March follow-up, issued after Iranian retaliation spread across the region, kept distance from the opening strikes but introduced language about necessary and proportionate defensive action.
London then published asummary of its legal positionthat confined British involvement to specific and limited defensive action in support of allies under attack.
The sequence mattered.
It showed not simple endorsement, but an effort to preserve legal distance while remaining operationally useful.
That distinction is harder to sustain than governments often suggest.
In a3 March NATO press conference, Mark Rutte described allied contributions as key enabling support.
The phrase was unusually candid.
Modern campaigns do not consist only of the states that visibly launch the strike.
Overflight permissions, basing, logistics, intelligence-sharing, refuelling, interception, and cyber support are integral to how force is projected.
AsMarko Milanovic notes, legal scrutiny cannot stop where trigger-pulling ends if enabling support is operationally decisive.
By mid-March, that ambiguity had become harder to sustain.
In Berlin,Friedrich Merz saidGermany would not participate in the war or in using military means to keep the Strait of Hormuz open whilehostilities continued, stressing theabsence of a UN, EU, or NATO mandate.
In Paris,Emmanuel Macron similarly ruled out French participation in operations to open or liberate Hormuz in the current context, while leaving open alater non-belligerent escort arrangement once the main bombardments had stopped.
In London,Keir Starmer insisted that any UK action required both a lawful basis and a viable, thought-through planand....
