This volume investigates the connection between intelligence history, domestic policy, military history and foreign relations in a time of increasing bureaucratization of the modern state. The issues of globalization of foreign relations and the development of modern, electronic means of communication are also discussed. With the de-classification of massive numbers of intelligence documents, particularly in the US and the former GDR, new insights into World War II and the Cold War are possible, for military and diplomatic historians as well as for cultural and political historians. Intelligence agencies were an indispensable tool for decision-making, for propaganda and for covert operations. What information was gathered and how it was linked to other relevant data reveals much about the mentality and perception of politicians and the military. This book sheds light on the domestic and social context in which intelligence organizations operated by comparing the workings of secret services in a democratic and a totalitarian regime.