Iran's Use of Cluster Munitions Against Israel Violates the Laws of War and May Constitute a War Crime

Since the outbreak of the current Iran-Israel conflict on February 28, 2026, Iranian forces have repeatedly deployed cluster munitions against populated centers inside Israel. The weapon’s mechanics are straightforward and its legal status is not: a ballistic missile releases its warhead in flight, dispersing dozens of unguided submunitions across an area up to thirteen kilometers wide. That dispersal pattern is incompatible with the foundational rule of distinction — the obligation under international humanitarian law to separate combatants from civilians before pulling the trigger.

Human Rights Watch confirmed three separate Iranian cluster munition attacks on Israeli population centers, documenting at least four civilian deaths: two construction workers killed in Yehud on March 9, and an older man and woman killed in Ramat Gan on March 18. A broader attack that day spread submunitions across Or Yehuda, Bat Yam, and Holon — impacts consistent with a single missile dispersing its payload across a multi-kilometer radius. The IDF has reported that approximately half of all Iranian ballistic missiles fired in this conflict have carried cluster warheads.

The legal case is not complicated by Iran’s non-membership in the 2008 Convention on Cluster Munitions, which 112 states have ratified. Customary international humanitarian law — binding on all parties regardless of treaty status — prohibits indiscriminate attacks under Article 51(4) of Additional Protocol I to the Geneva Conventions and Rule 1 of the CIHL, which requires parties to distinguish between civilians and combatants. HRW and Amnesty International have both concluded that Iran’s strikes fail that standard. Amnesty reached the same conclusion after documenting Iranian cluster munition use during the 12-Day War in June 2025. Launching an indiscriminate attack that kills civilians does not merely violate the laws of war — it constitutes a war crime.

The weapon also creates a secondary hazard that extends beyond the immediate strike. Submunitions that fail to detonate on impact function as de facto landmines, capable of killing and maiming civilians for years. Israel’s Home Front Command has already issued warnings instructing civilians not to approach unexploded ordnance — a familiar consequence in territories where cluster munitions have been used, and a preview of the long-term contamination these attacks are seeding across residential areas.

Iran’s tactical logic is visible in the weapon choice. With its ballistic missile launcher fleet degraded by U.S. and Israeli strikes, Iran has incentive to maximize casualties and disruption per missile. Cluster munitions serve that purpose: they overwhelm interception systems, force mass shelter responses across densely populated areas, and drive ongoing expenditure of costly Israeli and American interceptors. CNN reported that Iran’s use appears partly designed to impose economic and psychological attrition — suppression and exhaustion as a substitute for precision. The strategy is coherent. It is also illegal.

The counter-argument — that Israel is poorly positioned to condemn cluster munition use given its own documented deployment of more than four million such munitions in southern Lebanon in 2006 and reported further use in 2025 — is worth acknowledging and just as worth setting aside. Hypocrisy does not dissolve culpability. The question of whether Iran’s conduct constitutes a war crime does not hinge on Israel’s compliance record. It hinges on whether the attacks were indiscriminate, whether they killed civilians, and whether the weapon used was inherently incapable of distinguishing military from civilian targets. On all three counts, the answer is yes.

Iran has not responded publicly to HRW’s inquiry of March 25. The silence changes nothing about the legal exposure. What Iran is doing in the skies above Tel Aviv, Ramat Gan, and Beit Shemesh has a name in international law. The gap between that name and any prospect of accountability is, for now, vast — but the record is being built.