Deadly Magic: A Personal Account of Communications Intelligence in World War II in the Pacific

One of the most closely guarded secrets of World War II was the breaking of the Japanese military and diplomatic codes. It allowed continuous knowledge of Japanese plans and operations, and allowed victory against an enemy with sometimes greater forces. It enhanced the US submarine service against Japanese shipping. The author worked in Navy communications intelligence in Washington during the entire war. They read and translated intercepted messages. This 1978 book says FDR did not expect to provoke Japan into direct aggression against the United States (p.1). Scapegoats were found to placate a people shocked by Pearl Harbor, even if the scapegoats had not been told all (p.2). If it is true that military leaders prepare for the next war from their experiences in the last war, it is also true that those who fail to learn from the past are destined to relive it. In 1904 Japan attacked the Russian Far Eastern Fleet before they declared war. Destroying their fleet won the war; Japan had no hope or plan to invade on land. The loss of Hawaii would push America back to the West Coast, and America would not pursue this war with Hitler's Germany in control of Europe. America used the strategy of island-hopping to maximize its resources. They knew the enemy's strengths and weaknesses, their moves and countermoves. Destroying their merchant marine and oil tankers reduced their ability to defend effectively, and made attacks impossible. America's superior productive capacity and manpower would have won the war. Code breaking shortened the war by at least a year. This story on naval communications intelligence tells of the whole war in the Pacific, and other operations of the worldwide war.On Jan 27, 1941 Ambassador Grew in Tokyo reported the talk that Japan would begin war with "a surprise mass attack on Pearl Harbor" (p.58). Naval Intelligence stated "no move against Pearl Harbor appears imminent". The book "Day of Deceit" suggests more was known than was told.One mistake of the Japanese submariners was their disdain for merchant shipping. They learned nothing from WW I practices. Their pattern of shipping was not efficient either (p.153). The US knowledge of shipping location and contents allowed selective targets. Convoys were scorned because it was defensive, not offensive warfare. US submarines concentrated on tankers, this fuel shortage affected Japanese military operations (p.161).Chapter 8 tells about island-hopping - bypassing some of the most powerful Japanese bases because of limited resources. This was fortunate, since it avoided a higher number of casualties. Chapter 9 tells about the battle of Leyte Gulf, and how Admiral Halsey withdrew his fleet from San Bernadino Strait. While the Japanese fleet passed without hindrance, Admiral Kinkaid's fleet at Surigao Strait stood guard (p.188). Chapter 10 tells of the plan to use strategic bombing and a naval blockade to bring about a surrender without an invasion of Japan (p.204). Chapter 11 notes that