Humanitarian crises of the past 20 years reflect a changing political dynamic, in which the declining role of superpower regulation of regional and ethnic conflicts has contributed to the increasing prevalence of intra-state conflict and civil war. These crises, which typically occur in areas of grave underdevelopment or impoverishment, have trapped large numbers of people in environments torn by war, famine and disease. As evidenced in Afghanistan, Angola, Bosnia, Chechnya, Kosovo, Rwanda, Sierra Leone, Somalia, Congo, Sudan, and elsewhere, these crises are characterized by targeted attacks on civilians, mass population dislocation, widespread human rights abuses, and a high level of insecurity for responders.