A new international treaty that bans the stockpiling, use and transfer of virtually all existing cluster bombs and also provides for the clearing up of unexploded munitions, took effect earlier this week. But China, Russia, the United States, Israel, and other major cluster bomb-producing nations are among those who have refused to sign the accord.

We talk with Stephen Goose to find out how that could impact the effectiveness of the ban. Stephen Goose is Director of the Arms Division at Human Rights Watch and Co-chair of the Cluster Munition Coalition.