This classic of spy craft is based on Allen Dulles's incomparable experience as a diplomat, international lawyer, and America's premier intelligence officer. Dulles reveals much about how intelligence is collected and processed, and how the resulting estimates contribute to the formation of national policy. He discusses methods of surveillance, and the usefulness of defectors from hostile nations. His knowledge of Soviet espionage techniques is unrivalled, and he explains how the Soviet State Security Service recruited operatives and planted "illegals" in foreign countries. He spells out not only the techniques of modern espionage but also the philosophy and role of intelligence in a free society threatened by global conspiracies. It is a book for readers who seek wider understanding of the contribution of intelligence to our national security.