The Biden administration has taken a decision to provide Ukraine with cluster munitions as part of military aid for its ongoing war with Russia. This has evoked concern among human rights watchdogs, as cluster munitions are known to be a deadly cause of civilian casualties. More than 120 countries have signed a treaty that bans the production, use, stockpiling or transfer of cluster munitions. As it turns out, neither the US, nor Ukraine nor Russia are signatories of this convention. The US, however, does have a domestic law that bans the use, production or transfer of cluster munitions with a ‘dud rate’ above 1%. The dud rate of the cluster munitions being given to Ukraine, according to the State Department, is 2.35%, which is still above the 1% cap. So, what exactly are cluster munitions? What has prompted the US to offer them to Ukraine? And can they help Ukraine gain a decisive breakthrough in the war?