Oscar Johnson refused to back off from a claim that he was born and raised in center-city Detroit, where, he said, he first learned the principles of human diplomacy. He listed them in precise order–compromise, give-‘n’-take, courtesy, magnanimity. “An’ if you still don’ get what you want,” Oscar said, “then crack the sons of bitches with a sledgehammer.” Diplomacy, he was fond of saying, is the art of persuasion; and war–never citing his sources–is simply diplomacy continued through other means. . .