How Does the World Respond to a Genocide?

I became concerned about the failure of the world to respond to the genicide that was happening in rowanda, where eight hundred thousand people were murdered. And one way to study that was to look at why we help some le who are in danger, and not others. We found that this was very much related to how many people there were at risk. Why if we value individual lives so greatly, do we do so little to protect thousands or millions of lives at risk? That was the puzzle.