The Convention on Cluster Munitions is a response to the suffering caused by cluster munitions, which have killed and injured many thousands of civilians in countries where they have been used. In May 2008, 107 States concluded an international treaty prohibiting these weapons. The negotiations that led up to this were part of the “Oslo Process”, a Norwegian initiative whose aim was the conclusion of a treaty on cluster munitions by the end of 2008. The Convention was opened for signature on 3 December 2008 and entered into force on 1 August 2010. An important addition to international humanitarian law (IHL), the Convention reinforces fundamental customary IHL rules that are applicable to all States. These rules require parties to a conflict to distinguish at all times between civilians and combatants, to direct operations only against military objectives and to take constant care to spare civilians and civilian objects. On the basis of this Convention, cluster munitions are considered – like exploding and expanding bullets, chemical weapons, biological weapons, anti-personnel mines, weapons using undetectable fragments and blinding lasers – as weapons prohibited under IHL.