Author: Akanksha Jamre, Prestige Institute of Management and Research Indore
Introduction
In mid-June 2025, Israel launched Operation Rising Lion, conducting air and drone strikes on nuclear and military facilities across Iran. Iran responded with missile and drone attacks targeting Israeli civilian infrastructure and medical facilities. The conflict escalated further when the U.S. joined with strikes on Iranian nuclear targets. A fragile ceasefire now holds.
But beyond the geopolitical and military aspects, this conflict raises critical legal questions under international law: Are these attacks lawful under the UN Charter Do they constitute humanitarian law violations or acts of aggression? What accountability mechanisms exist?
Jus ad Bellum: The Law Governing Use of Force
a. Article 2(4) & the UN Charter
The UN Charter expressly prohibits the use of force against another state’s sovereignty, territory, or political independence—except in two scenarios: Security Council authorization (Chapter VII) or self-defence under Article 51.
b. Self-Défense: Article 51, Scope & Conditions
Article 51 allows “individual or collective self-defence” in the situation of an armed attack. Unless and until the security council intervenes.
Israel claims that its action was taken for self-defence against Iran’s nuclear development
Legal thresholds for such action derive from the 19th-century Caroline doctrine: any pre-emptive strike must meet conditions of instant, overwhelming threat, with no time for deliberation, and be proportionate—very high standards
Conflictual interpretations:
Critics (e.g., EBS’s Matthias Goldmann, UN experts) see no imminent threat, labeling the action as preventive—illegal under international law.
Israel and its allies, notably the G7, contend that arguments for collective defense are made possible by a larger, continuous pattern of Iranian hostility (via proxies and nuclear talk).
c. Precedents: Osirak & the Six-Day War
Israel’s 1981 Osirak strike and 1967 Six-Day War have historically been cited both as precedents for anticipatory self-defence and as breaches of international law, e.g., UNSC Resolution 487 condemned Osirak
However, commentary from the ICJ, International Commission of Jurists, and legal scholars consistently holds that today’s strikes likely fall short of legal justifications unless imminence is convincingly established
d. Conclusion on Jus ad Bellum
While allies may politically endorse Israel and the U.S. actions, most public international legal opinion treats these strikes as exceeding permissible self-defence, constituting unlawful aggression under Article 2(4). The situation reflects deep divides: legalists stressing clear thresholds, and realists framing ongoing conflicts and proxy dynamics as justification.
Jus in Bello: Conduct in Armed Conflict
Assuming an International Armed Conflict (IAC) exists (supported by repeated Israeli attacks on Iranian targets since 2024), certain rules apply regardless of jus ad bellum
a. Distinction, Proportionality, Precaution
Both parties must:
Distinguish between combatants and civilians.
Ensure proportionality, avoiding civilian harm disproportionate to military objectives.
Take precautions, including advance warning where feasible.
b. Alleged Violations
The UN fact-finding mission flagged strikes on an apartment complex, hospital, clinic, and death of medical staff—with failures to give effective warning—raising serious international humanitarian law concerns. The targeting of nuclear scientists raises legal questions around civilian status versus direct participation
Iran’s retaliatory missile fire, largely intercepted, may have skirted military targets. Any civilian impact would similarly trigger scrutiny.
c. Diplomatic Premises & Consular Immunity
Separate strikes—like Israel’s attack on Iranian diplomatic premises in Damascus—fall under protections of the Vienna Conventions and Article 2(4). UN experts warn that such strikes run the risk of being considered separate violations in the absence of a legitimate self-defense justification.
d. Weapons Safety & Nuclear Sites
Attacks on nuclear facilities risk radioactive release, violating IAEA protections and raising critical safety concerns, as noted by ICJ and IAEA. These facilities are part of specially protected infrastructure.
Accountability & Mechanisms
a. United Nations Bodies
Security Council: Could deem actions illegal and recommend measures—but faces veto paralysis.
International Commission of Jurists (ICJ): Already condemned the strikes as violations of international law and urged UNSC action.
b. International Criminal Court (ICC)
While ICC indictments focus on Gaza-related actions, the court holds jurisdiction over war crimes and crimes of aggression.
Individuals responsible for strikes with civilian harm or aggression claims may face prosecution, though Israel is not a State Party. Universal jurisdiction states could still prosecute senior commanders.
c. Domestic & Diplomatic Reactions
Australia sought formal legal advice but supported U.S. and Israeli actions
Many Global South and Islamic nations—aligned with ICJ—condemn the conflict and may pursue collective diplomatic or legal resistance.
Legal Status of Nuclear Facilities as Targets
The legitimacy of attacking nuclear installations during a conflict is another important concern. Works and installations that contain harmful forces, such as nuclear power plants, are particularly protected from attack under Additional Protocol I to the Geneva Conventions (Article 56). Attacks must prevent the possibility of serious civilian casualties from radioactive exposure, even if they are utilized for military objectives.
In the June 2025 conflict, Israel’s strikes on Iranian nuclear sites—including Natanz and Fordow—raise concerns about whether due regard was given to environmental and civilian safety. The IAEA (International Atomic Energy Agency) issued statements warning of potential contamination and breach of safety protocols.
Customary international law also prohibits the use of methods or means of warfare that cause widespread, long-term, and severe damage to the natural environment (Rome Statute, Article 8(2)(b)(iv)). The use of bunker-busting ordnance in populated or unstable geological zones may increase environmental risks disproportionately to the military gain.
Furthermore, there is debate over whether Iran’s nuclear program, under IAEA oversight, constitutes a valid military target. Unless these sites are being actively weaponized or used in direct military planning, targeting them could fall afoul of IHL’s distinction and necessity principles.
While Israel argues that Iran’s nuclear ambitions constitute a legitimate existential threat, legal scholars caution that fear of future misuse does not override the immediate requirement for imminence and proportionality under both jus ad bellum and jus in bello.
Strategic & Normative Implications
a. Precedential Risks
The normalization of pre-emptive preventive strikes undermines the rules-based order, feeding potential abuse by future powers under weak imminence claims. Critics, including FT and Washington Post, warn that only diplomacy provided durable nuclear containment.
b. Erosion of Legal Standards
Allowing one state to strike another on broad grounds threatens the Caroline test, Article 2(4), and international legal thresholds. Scholars like Ben Saul argue such exceptions dangerously erode legal integrity.
c. Regional Arms Races & Stability
Escalatory dynamics—cyber, drone, ballistic—could spiral if legal constraints unravel. Gulf states face heightened nuclear anxiety amid worries Iran may abandon the NPT.
Recommendations & Paths Forward
a. Renewed Diplomacy
Resurrect multilateral diplomacy akin to the 2015 JCPOA, expanded to address missiles and
Empower the IAEA with access and enforceable mandates.
b. Legal Clarifications
The UN Security Council or ICJ should offer clear declaratory rulings on the legality of preventive strikes.
Establish higher threshold requirements for self-defence claims—such as clearer definitions of imminence.
c. Accountability Guarantees
Conduct unbiased fact-finding while safeguarding witnesses and supporting documentation.
Launch diplomatic and legal measures, including sanctions or case referrals, to ensure deterrence and compliance.
Conclusion
The Israel–Iran war underscores a critical inflection point for international law. While states seek security guarantees—even existential ones—the legal frameworks governing use of force, distinction, and sovereignty must hold firm. The prevalent legal opinion views these June 2025 strikes as unlawful, lacking sufficient imminence or proportionality. As international law evolves, it will require firm reaffirmation through diplomacy, accountability, and jurisprudence. Learning from this conflict may shape whether the world preserves a binding rules-based order—or succumbs to strategic could-justify militarism.
FAQS
Q1: Is anticipatory self-defence legal under international law?
Anticipatory self-defence remains controversial. Under Article 51 of the UN Charter, states can use force only in response to an actual or imminent armed attack. The Caroline doctrine allows anticipatory self-defence only when the threat is instant, overwhelming, and leaves no choice of means. Most legal scholars reject pre-emptive strikes as lawful without clear imminence.
Q2: Can attacks on nuclear facilities be lawful?
Yes, but only under strict conditions. Attacks must meet the criteria of military necessity and proportionality, and avoid causing catastrophic civilian or environmental harm. Protocol I (Article 56) restrict such strikes, and customary law demands special caution due to potential radiation risks.
Q3: Do cyberattacks count as armed attacks?
Sometimes. If a cyber operation causes effects equivalent to a kinetic strike—like destruction of infrastructure or death—it may qualify as a “use of force” under Article 2(4) and possibly trigger Article 51 rights of self-defence.
Q4: Can non-state actors trigger lawful self-defence?
Yes, but only if their attacks are attributable to a state (e.g., they are directed, supported, or harboured by a state). If attribution is lacking, self-defence against the territorial state may be unlawful.