In October 1941, the United States was the only major industrial power still neutral. But that status was becoming increasingly tenuous. Off its east coast, America sailed a dangerous diplomatic course between two belligerents involved in a shooting war in the Atlantic Ocean. The country’s situation off the west coast was little better; there the question of shooting began with the interrogative adverbs “when” and “where,” not the conjunction “if.” In early 1941, President Franklin Roosevelt appointed Adm. Ernest King commander in chief of the newly organized Atlantic Fleet. When informed of his appointment, King said, “When they get into trouble they send for the sons of bitches.” King would need every bit of his celebrated intestinal fortitude, because he was...