Last month the Naval Institute Press published Joe Rochefort’s War: The Odyssey of the Codebreaker Who Outwitted Yamamoto at Midway by Elliot Carlson. The book is the first biography of the officer who headed the Navy’s decryption unit at Pearl Harbor and began to break the Japanese navy’s code before the Battle of Midway. Based on his unit’s interpretations of the coded Japanese messages, Rochefort believed Japanese Combined Fleet Commander Isoroku Yamamoto’s invasion target would be Midway. His conclusions and the U.S. Navy victory there changed the course of the war.
Captain Joseph J. Rochefort was among the first people the Naval Institute interviewed in 1969 for its fledgling Oral History Program. Two years later, the Office of Naval Intelligence requested the Institute forward its completed series of Rochefort interviews to the National Security Agency (NSA), which classified it Secret Codeword, confiscating the tapes and transcript to prevent further use. In 1983 the NSA returned an unclassified, sanitized version of the oral history to the Institute with approximately 95 percent of the original manuscript intact.