Explainer
Cluster Munitions Explained: Why They Are Banned by Many Countries
Cluster munitions scatter multiple explosive submunitions over an area and can leave dangerous unexploded remnants. A 2008 treaty prohibits them for States Parties.
Reviewed 18 September 2026. This is an evergreen explainer; case-specific legal findings should be checked against the newest authoritative source.
In short: Cluster munitions scatter multiple explosive submunitions over an area and can leave dangerous unexploded remnants. A 2008 treaty prohibits them for States Parties.
Cluster munitions are weapons designed to disperse or release multiple explosive submunitions over an area. Their humanitarian impact has two stages: wide-area effects at the time of attack and unexploded submunitions that can remain dangerous long after fighting ends.
How cluster munitions work
A larger container releases smaller explosive submunitions—sometimes called bomblets—over a target area. Because the submunitions can spread across a broad footprint, civilians and civilian objects within or near that area can face high risk, particularly in towns and cities.
Why unexploded submunitions matter
Not every submunition detonates as intended. Duds can remain in fields, roads, buildings and school grounds, acting like unexploded ordnance for years. They can obstruct farming, reconstruction, return of displaced people and ordinary movement.
The Convention on Cluster Munitions
The 2008 Convention prohibits States Parties from using, developing, producing, acquiring, stockpiling, retaining or transferring cluster munitions as defined by the treaty. It also contains obligations concerning stockpile destruction, clearance and victim assistance.
Not every State is party to the treaty
Treaty prohibitions bind States Parties. States outside the Convention remain bound by general IHL rules governing the conduct of hostilities and by any other applicable treaty or customary rules. Reporting should therefore distinguish “prohibited for this State under the Convention” from a universal treaty ban applying identically to all States.
Why terminology matters
Not every weapon that releases multiple effects is legally a cluster munition under the treaty definition. The Convention contains technical criteria and exclusions. Journalists should avoid identifying a munition solely from a distant image when specialist verification is unavailable.
After the strike, contamination becomes a long-term crisis
Clearance teams must locate, mark and destroy unexploded submunitions. Risk education and survivor assistance may continue for decades, meaning the humanitarian cost can outlast the military operation that created the contamination.
Frequently asked questions
Are cluster munitions the same as landmines?
No. They are different weapons, though unexploded submunitions can create mine-like long-term hazards.
Are cluster munitions banned everywhere?
The Convention bans them for its States Parties; not every State is party.
Why are civilians harmed years later?
Unexploded submunitions can remain active after the conflict and detonate when disturbed.