In this balanced and thought-provoking study, Russell Crandall examines the American decision to intervene militarily in three key episodes in American foreign policy; the Dominican Republic, Grenada and Panama. Drawing upon previously classified intelligence sources and interviews with policymakers, Crandall analyzes the complex deliberations and motives behind military intervention in each case. He argues that in all three instances, the decision to intervene was driven by a perceived threat to American national security.