Reviewed by Arne Kislenko, Department of History, Ryerson University.
Published by H-Diplo (March, 2001)

Nearly sixty years after it began, the war between Japan and the United States continues to stir considerable controversy. Whether it is discussion about Japan's apparent unwillingness to acknowledge its sordid past, or a debate on morality and dropping the atomic bomb, there is no shortage of contention. For his battleground, Keiichiro Komatsu has chosen, broadly, the origins of the conflict, and, specifically, the role played in starting the war by deciphered Japanese diplomatic communications - commonly referred to by the American code-name MAGIC.

Although often confusingly assumed to refer to all deciphered Japanese communications during the war, MAGIC more precisely included decrypted diplomatic codes and ciphers. The most valuable, and best known, were those encrypted by the cipher machine Americans nick-named "PURPLE". Cracking PURPLE's codes was an extremely daunting challenge, ultimately taken up and bested by a team of dedicated cryptanalysts from the U.S. Army Signal Intelligence Corps. With the codes cracked, the U.S. was able to read most of the secret diplomatic communications used by the Japanese from shortly before the attack on Pearl Harbour until the end of the war. This ability (which was so remarkable it was "magic"), provided officials in Washington with a tremendous advantage in dealing with Japan during negotiations in the summer and autumn of 1941 to avoid a conflict. However, according to Komatsu, the information that MAGIC provided was predicated on many mistranslations and distortions. Hence, MAGIC was significant in contributing to the "cumulative effect of misunderstanding in the negotiations preceding the Pacific War" (preface).

The Origins of the Pacific War and the Importance of Magic is divided into four parts, dealing with the historical legacy between Japan and the United States, turning points in the negotiations before the war (in two parts), and MAGIC as a cause of misunderstanding between the two countries. Komatsu spends a great deal of time examining modern Japan's history vis-a-vis the West, discussing the impact of events and issues such as the Russo-Japanese War, the "Open Door" concept in China, World War I, post-war naval disarmament negotiations, the Japanese incursion in Manchuria, and the invasion of China. Throughout he weaves a prevalent theme of mutual mistrust between Japan and the United States that ultimately came to dominate their relationship by the late 1930s. Komatsu also deals extensively with structural elements in both nations' decision-making, stressing that Japanese leaders were far more divided, and frequently confused, on foreign policy questions than was assumed at the time by those in the West. In addition to failing to understand what China meant to the United States, Komatsu contends that Japanese leaders consistently misinterpreted American policies as aggressive rather than deterrent. Whereas under Franklin Roosevelt the U.S. pursued a "cautious and coercive" approach of firm deterrence towards Japan, Japanese leaders saw a provocative America, intent on conflict (p. 143-148).

Placing MAGIC at the heart of this misunderstanding, Komatsu then traces the many problems that existed in interpreting Japanese diplomatic codes. He argues that the potential for error in the multi-tiered decryption process was considerable, especially when considering the particularities of the Japanese language. To further the point, Komatsu presents an impressive list of mistranslations, clearly indicating how the nuances of language might have affected decision-making in the U.S. at the time. Komatsu uses the so-called Hull Note of November 1941 to stress this contention. After rejecting Japanese proposals on negotiations, the U.S. Secretary of State, Cordell Hull, submitted the American terms, which effectively represented the Roosevelt's administration increasing hard-line, and which came to be seen in Japan as an outright ultimatum. Komatsu argues (against many historians) that "the efforts made by the participants on both sides to achieve a successful outcome and avert the conflict, or at least to delay the outbreak of war until the following March of 1942, might have been much closer to achieving success than is generally believed up to now" (p. 289). However, mistakes in MAGIC were key in influencing American decision-makers against attempts at negotiations. For example, the Japanese plan for negotiations, Proposal A (Ko-an), sent from Tokyo to Ambassador Nomura in Washington on November 4th, 1941, had "a meaning opposite to that of the original text" when translated by MAGIC (p. 295). Similarly, a telegram sent on November 11th, 1941 from the Japanese Foreign Ministry to Nomura was mistakenly translated as calling for the "establishment" of negotiations with the U.S., when in fact it called for the "conclusion" of talks. These mistakes, Komatsu argues, led American officials to believe that Japan was dragging its heels on negotiations, when in fact they were a priority for Tokyo (p. 303). Hence, the Hull Note, and a major step towards war. While Komatsu points out that the mistranslations were not purposeful, he stresses that MAGIC interpreters often misled American decision-makers by "arbitrarily inserting" certain terms or punctuation (p. 296), while occasionally omitting key Japanese words.

In addition to questioning the accuracy of MAGIC, Komatsu challenges many generally accepted notions about the road to war between Japan and the United States. For example, he consistently presents Cordell Hull as more of a moderate - even a dove - on Japan, relative to hard-liners like Harold Ickes or Hans Morganthau. While acknowledging the increasing militancy of Japanese foreign policy, Komatsu also argues that right up until November 1941 neither the Japanese Army nor the Navy saw victory over the United States as possible. He points out that contrary to his fearsome reputation in the West, Hideki Tojo was appointed as prime minister in October 1941 to bridge the many gaps that existed in the Japanese government and armed forces, and, more importantly, to pursue negotiations - not war - with the Americans (p. 290-291). Komatsu argues that even after receipt of the Hull Note Japan was not anxious to engage the U.S., and that a "complicated process" still existed within the Japanese government before the fateful decision for war would be made (p. 312).