Defectors are a phenomenon that governments both fear and seek. They repudiate the system from which they came, and, if they held a position of trust, they reveal to the receiving side information about the inner workings of their former country. For the losing side, this can be catastrophic, while for the receiving side it can be a unique and valuable source of information. This book explores defectors from a closed political system– the Soviet Union of the 1920s to 1950s– determining the insights they gave into a notoriously opaque Soviet decision-making process.

For the purposes of this book, a defector is a person who renounces allegiance to one state or cause in exchange for allegiance to another, in a way that the losing side considers illegitimate. While the phenomenon of defection is not unique to states and may affect any organisation, such as a political party or a corporation, this book focuses on defectors from a state, especially a state with a closed political system. A closed political system is one that allows little or no transparency into the decision-making process that governs it. In a closed political system, the authority to change the system is reserved only for a ruling elite; the elite has power over the whole society, leaving no group immune from its control; and laws are constructed to satisfy the demands of the elite. Typically, those outside the elite have little influence on or visibility into the elite's plans, which is accentuated for those outside the system entirely. The domestic and international goals and objectives of a closed political system are known only to a privileged few. Hence, when such a system interacts on the international stage, it obscures its strategies and plans that are focused largely on the interests and survival of the elite. This book examines how the compounded revelations of one category of the Soviet elite, intelligence officers, opened a window into Soviet national security decision-making.

When defectors leave their home and relocate to a new state, they take with them the information they possessed before defection and often communicate it to the receiving state. This is particularly true of intelligence officer defectors, who have privileged access to sensitive information that a government takes great care to keep secret.