Saturday marks the 25th anniversary of the Srebrenica massacre, in which Bosnian Serb forces killed about 8,000 Muslim men and boys during the Balkan conflict in the largest genocide in Europe since the Holocaust. Some war criminals, such as Ratko Mladic and Radovan Karadzic, did not faced justice until recent years, while others are still free. In the years since Srebrenica, other war crimes have been perpetrated today in major conflict zones such as Yemen and Syria. So what is the world doing about these ongoing international crimes? Host Carol Hills speaks with David Scheffer, former US ambassador-at-large for war crimes issues from 1997 to 2001.