After each war, historians sift through the record to discern its real causes. Invariably, they divide into two camps: the court historians who defend the war leaders and the revisionists who prosecute them before the bar of history. After World War II, the evidence that FDR had steered us into war, while asserting he was doing his best to avert war, was so massive even his court historians admit he lied. Wrote Thomas A. Bailey in FDR's defense, "He was like the physician who must tell the patient lies for his own good." Roosevelt had cut off Japan's oil, sent...