Matthew Akins is a contributing writer at the New York Times magazine. He's reported from Yemen on exactly what cluster munitions do to combatants and civilians. Cluster bombs have gained a reputation for killing and injuring civilians, especially children who come across smaller explosives or bomblets that fail to initially detonate after being dropped. Because of the danger they pose to innocent people, these weapons are very controversial and a lot of countries have banned them outright. They've been used in many conflicts since World War II but were last used by US during invasions of Afghanistan and Iraq.