To witness kith and kin dying of poverty is the worst humiliation. We are at our weakest, at our most powerless and vulnerable, when we cannot help those for whom we care attain the food, water, and shelter necessary for survival. There is a sense of injustice and of abject failure when children perish from malnutrition and disease, or when the old, the sick, and the innocent are left behind on roads and paths leading away from epochal violence and crisis.

A global epidemic of violence and poverty marks the contemporary world. Formal wars between nation-states have declined, but civil conflict, sectarian bloodletting, and other forms of violence have been increasing, from suicide bombing and narco-terrorism to rape as an instrument of war. At the beginning of the new millennium, more than forty-five armed conflicts were being waged, many of them in Africa, where some wars have been grinding on for four decades or more. More generally, the past two centuries have witnessed violence that is so nearly unimaginable that it has strained our very capacity to describe and understand a world in which so many have died.