Book excerpt: State failure, ethnopolitical war, genocide, famine, and refugee flows are variants of a type of complex political and humanitarian crisis, exemplified during the 1990s in places like Somalia, Bosnia, Liberia, and Afghanistan. The international consequences of such crises are profound, often threatening regional security and requiring major inputs of humanitarian assistance. They also may pose long-term and costly challenges of rebuilding shattered governments and societies. A vital policy question is whether failures can be diagnosed far enough in advance to facilitate effective international efforts at prevention or peaceful transformation. This volume of original essays examines crisis early warning factors at different levels, in different settings, and judges their effectiveness according to various models. Top contributors offer answers along with analyses as they move from early warning to early response in their policy recommendations.