ONYX has documented Iranian civilian strike accusations against the US across the production arc. ONYX applies the same accountability standard to documented Iranian violations of the laws of armed conflict as it applies to documented US incidents. The cluster munition story is the specific accountability of Iranian military conduct in this war, documented at its confirmed level.
THE FACTS
▸ By day 10 of the war, Iran had fired 300 missiles at Israel
▸ Nearly half of those 300 missiles carried cluster submunitions
▸ Cluster submunitions: explosive warheads that disperse dozens to hundreds of individual bomblets over a 10-kilometer radius; bomblets that fail to detonate on impact become de facto landmines
▸ The Convention on Cluster Munitions: bans the production, transfer, and use of cluster munitions; signed by more than 100 nations
▸ Iran, Israel, and the United States have not signed the Convention
▸ 24 Israeli civilian deaths have been directly attributed to cluster munition strikes
THE LEGAL DIMENSION
Iran has not signed the Convention on Cluster Munitions. Its use of cluster munitions is therefore not a treaty violation — it cannot violate a treaty it is not party to. What it may violate is customary international humanitarian law: the prohibition on indiscriminate weapons whose effects cannot be controlled is an IHL principle that applies to signatories and non-signatories alike. Cluster munitions’ wide-area effect and high dud rate make their use in populated civilian areas a specific customary IHL concern.
THE SYMMETRY OF ACCOUNTABILITY
The US also has not signed the Convention on Cluster Munitions. The US has used cluster munitions in prior conflicts. ONYX covers the Iranian cluster munition use at the same accountability level it covers US civilian strike incidents: the laws of armed conflict and customary IHL apply to all parties; what matters is the evidence of what occurred and what legal framework applies, not the political alignment of the party being assessed.
Iran fired cluster munitions at Israeli cities. Twenty-four Israeli civilians died. Cluster munitions are banned by more than 100 countries. Iran is not one of them. The US and Israel are not either. The accountability of cluster munitions is not specific to one side of this war.
WHAT HAPPENS NEXT
▸ IHL review — whether any international body formally assesses Iranian cluster munition use under customary IHL
▸ Israeli government — whether Israel formally raises cluster munition use in international forums
▸ US position — whether the US, which has not signed the Convention, can formally object to Iranian use
| CONFIDENCE: HIGH | 300 Iranian missiles in war’s first 10 days, nearly half with cluster munitions, Convention on Cluster Munitions 100+ signatories, Iran/Israel/US non-signatory, 24 Israeli civilians killed by cluster strikes from verified reporting. |
SOURCES
▸ Verified reporting — Iran cluster munitions Israel 300 missiles, September 4, 2026
