Book excerpt: Today's international war crimes tribunals lack police powers, and therefore must prod and persuade defiant states to co-operate in the arrest and prosecution of their own political and military leaders. Victor Peskin's comparative study traces the development of the capacity to build the political authority necessary to exact compliance from states implicated in war crimes and genocide in the cases of the International War Crimes Tribunals for the former Yugoslavia and Rwanda. Drawing on 300 in-depth interviews with tribunal officials, Balkan and Rwandan politicians, and Western diplomats, Peskin uncovers the politicized, protracted, and largely behind-the-scenes tribunal-state struggle over co-operation.