Diplomatic realism demands that diplomats deal with a flawed world the way it is. Mankind has consistently evinced the capacity both to compete for resources and to cooperate with others having similar self-interests. For W.R. Castle the wise statesman was the one who could manage and constructively channel both tendencies. Castle believed that misdirected and self-righteous moral fervor could destabilize the delicate international order. Idealists, pursuing abstractions, usually ignored the historical fact that moral choices must be made in the context of political action with all of the...