fills two important gaps in the literature on the ethics of national security affairs. First, while thinking about the justice of warfare is highly developed, justifications of intelligence activities—which can involve lying, manipulation, coercion, stealing and even killing to obtain and defend information—are relatively limited and often conflicting. The authors explore relevant ethical principles and then apply them to specific activities—including agent recruitment, human and technical methods of espionage and counterintelligence, interrogational torture, analysis, covert action, sabotage, and assassination.     Second, ethical work on interstate conflict occurring in a “gray zone” between war and peace has only just begun. Gray zone operations—the use of low-level lethal and sublethal means to weaken others—are not new. But technological developments have increased the forms, intensity, and significance of this realm of competition. This volume defines the gray zone and discusses moral challenges associated with various operations—including lethal, economic, information, election, legal, and cyber.