Cluster bombs were also used in the 1999 war in Kosovo . China , Russia absent from signing of cluster bomb ban treaty signing . U.S. , China , United States , Russia are top four cluster bomb producers . United States insists the devices are important part of its defense strategy .
China , Russia absent from signing of cluster bomb ban treaty signing . U.S. , China , United States , Russia are top four cluster bomb producers . United States insists the devices are important part of its defense strategy .