The Polish Underground and the Jews, 1939–1945 examines one of the central problems in the history of Polish-Jewish relations: the attitude and the behavior of the Polish Underground – the resistance organization loyal to the Polish government -in-exile – toward the Jews during World War II. Using a variety of archival documents, testimonies, and memoirs, Zimmerman offers a careful, dispassionate narrative, arguing that the reaction of the Polish Underground to the catastrophe that befell European Jewry was immensely varied, ranging from aggressive aid to acts of murder. By analyzing the military, civilian, and political wings of the Polish Underground and offering portraits of the organization's main leaders, this book is the first full-length scholarly monograph in any language to provide a thorough examination of the Polish Underground's attitude and behavior towards the Jews during the entire period of World War II.