This book is dedicated to how diplomacy makes, develops, and trades in knowledge. It proposes an approach to examine how diplomatic knowledge production describes what diplomats see, how these descriptions develop, and whether they were convincing to one's own policymakers or even those of other actors. These descriptions are vital: actors can be inserted into global categories Communism or Terrorism that beget significant security, relational and policy consequences. Diplomacy and policy constitute the world we inhabit based on what policymakers made of descriptions, assessments, and analysis. Such is the power of knowing who we and the others are.