This sweeping history of the development of professional, institutionalized intelligence examines the implications of the fall of the state monopoly on espionage today and beyond.

During the Cold War, only the alliances clustered around the two superpowers maintained viable intelligence endeavors, whereas a century ago, many states could aspire to be competitive at these dark arts. Today, larger states have lost their monopoly on intelligence skills and capabilities as technological and sociopolitical changes have made it possible for private organizations and even individuals to...