The history of secret intelligence, like secret intelligence itself, is fraught with difficulties surrounding both the reliability and completeness of the sources, and the motivations behind their release—which can be the product of ongoing propaganda efforts as well as competition among agencies. Indeed, these difficulties lead to the Scylla and Charybdis of overestimating the importance of secret intelligence for foreign policy and statecraft and also underestimating its importance in these same areas—problems that generally beset the actual use of secret intelligence in modern states. But in recent decades, traditional perspectives have given ground and judgments have been revised in light of new evidence. This volume brings together a collection of essays avoiding the traditional pitfalls while carrying out the essential task of analyzing the recent evidence concerning the history of the European state system of the last century. The essays offer an array of insight across countries and across time. Together they highlight the critical importance of the prevailing domestic circumstances—technological, governmental, ideological, cultural, financial—in which intelligence operates. A keen interdisciplinary eye focused on these developments leaves us with a far more complete understanding of secret intelligence in Europe than we've had before.