- Z Plan (Japan)
The Z Plan is a set of captured
World War Two documents describing Japanesemilitary plans to counterattack the Americans in the centralPacific ocean for one last decisive battle. The capture and exploitation of this information was one of the most importantmilitary intelligence achievements of thePacific War .The Z Plan was developed under the leadership of Admiral
Mineichi Koga , commander in chief of the Japanese Combined Fleet, and was approved by theImperial Japanese Navy General Staff . The plan was formally titled: Combined Fleet Secret Operations Order No. 73, with the final version issued on March 8, 1944. On April 1, en route toDavao , Admiral Koga's plane crashed into the ocean during a bad storm, killing Koga and everyone else aboard. Admiral Koga's chief of staff, Rear Adm.Shigeru Fukudome , carrying a copy of the Z Plan, was traveling the same itinerary in a separate plane. This second plane crashed nearCebu Island after attempting to avoid the same storm. Fukudome and nine others eventually made it to shore, where they were captured by local Filipinoguerrilla s who were supportive of the U.S. forces.Because of the loss of the two planes, with their high-level occupants and important documents (Japanese ocean-current experts believed documents would eventually wash-up on shore), the Japanese applied intensive pressure on the local population. Partially as a result of this pressure, Fukudome and the others were eventually released.
On April 3, a wooden box from Fukudome's plane washed up near shore, and was secretly recovered by two villagers. The box contained the Z plan, a bound document in a red leather portfolio, with a Z on the cover. The documents eventually made it into the hands of the local guerrilla organization, the Cebu Area Command. The ornate nature of the documents led the CAC and their American handlers to suspect the documents were very important, a suspicion that was later reinforced by Japan's offer of a large reward for the return of any documents.
A clandestine high-priority
submarine pickup was arranged, with acover story of evacuating American refugees. The submarine picked up the documents, along with 40 American men, women and children. Traveling mostly on the surface for speed, and diving only when needed, the submarine surviveddepth charging twice, arriving near the American naval base in Darwin, Australia on May 19. From there the documents were flown to Brisbane.The Z Plan documents were in
plain text , rather than code, and were translated on an urgent basis by the top five translators at theAllied Translator and Interpreter Section . Copies of the translation were rushed to GeneralDouglas MacArthur , who quickly forwarded them to AdmiralChester Nimitz , commander in chief of the Pacific Fleet (and Admiral Kogo's counterpart). Among other things, planned Japanese diversionary tactics were now anticipated by the Americans, leading to the lopsided American victory in theBattle of the Philippine Sea , the largestaircraft carrier battle in history, and the decisive battle of the Pacific war.References
http://www.archives.gov/publications/prologue/2005/fall/z-plan-1.htmlThe "Z Plan" Story - National Archives Prologue Magazine
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