MacArthur's ULTRA : codebreaking and the war against Japan, 1942-1945

Modern War Studies Theodore A. Wilson General Editor Raymond A. Callahan J. Garry Clifford Jacob W. Kipp Jay Luvaas Series Editors

MacArthur's

ULTRA

Codebreaking and the War against Japan, 1942-1945 Edward J. Drea

o

University Press of Kansas

if t:rl1 '1 o

1'f1 ,fJt ft (t:i72/ For my mother, Joan Lavene Drea

Š 1992 by the

University Press of Kansas All rights reserved

Published by the University Press of Kansas (Lawrence, Kansas 66(49), which was organized by the Kansas Board of Regents and is operated and funded by Emporia State University, Fort Hays State University, Kansas State University, Pittsburg State University, the University of Kansas, and Wichita State University Library of Congress Cataloging-in-Publication Data Drea, Edward J., 1944MacArthur's ULTRA: codebreaking and the war against Japan, 1942-1945/ Edward J. Orea. p. em. - (Modern war studies) Includes bibliographical references (p. ) and index.

ISBN 0--7006-0504-5 Calk. paper) ISBN 0--7006-0576-2 Cpbk.)

'I. World War, 1939-1945-Campaigns-Pacific Area.

2. World War, 1939-1945-Cryptography. 3. World War, 1939-1945-Military intelligence-Pacific Area. 4. MacArthur, Douglas, 1880-1964Military Leadership. 5. Pacific Area-History. 1. Title.

II. Series.

0767.066 1991 940.54'26-dc20 91- 16842 British Library Cataloguing in Publication Data is available.

Printed in the United States of America 10

9

8

7

6

5

4

The paper used in this publication meets the minimum requirements of the American National Standard for Permanence of Paper for Printed Library Materials Z39.48-1984.

Contents

List of lliustrations and Tables

vii

Preface

xi

MacArthur's Codebreaking Organization

2

ULTRA'S

Trials and Errors, 1942

3 Breaking into the Japanese Army Codes, January 1943January 1944 4

5

Great Victory: The Hollandia Operation, JanuaryApril 1944

1

32 61

ULTRA'S

Misreading

ULTRA,

May-September 1944

94 123

6 The Missing Division: Leyte, 1944

152

7 The Numbers Game: Luzon, January-June 1945

180

8

9

as Seer: Uncovering Japanese Plans for Homeland Defense, June-August 1945

202

Conclusion

226

ULTRA

Notes

237

A Note on Sources

271

Selected Bibliography

275

Index

283

Illustrations and Tables

Figures

1.1

A Sample Page from the Japanese Army Code Book

3

1.2

A Typical Japanese Army Message Enciphered for Transmission

4

1.3 The Mainline Radio Network, Imperial General Headquarters

5

1.4 The Japanese Army Message in Figure 1.2 Transmitted in Morse Code

6

2. 1 Abbreviated Army Chain of Command

35

Photographs

Willoughby visits Akin's headquarters, Bataan, 1942

14

The fIrst American cryptanalysts in front of the Henry Street headquarters of Central Bureau, 1943

20

B-25s attack a Japanese transport during the Battle of the Bismarck Sea, 1943

65

Blarney visits the codebreakers at Twenty-One Henry Street, 1943

80

Planning the leap to Hollandia, 1944

111

Members of Central Bureau's Hut 7, 1944

113

viii

Illustrations and Tables

Listening to the enemy-radio intercept operators of the 126th Signal Radio Intelligence Company, mid-1944

145

The underground radio communications center of 86th Division Headquarters near Ariake Bay in southern Kyushu

205

A representative of each of the services at Central Bureau, 1945

227

Maps

The Pacific Areas

17

Papua New Guinea Operations

45

Southwest Pacific Actions, January-October 1943

69

CARTWHEEL Operations, October 1943-February 1944

88

Anticipated and Actual Allied Landings, April 1944

114

Allied Landings, New Guinea, April-May 1944

125

Leyte

165

Luwn Operations

190

Disposition of Forces, Kyushu

221

Tables

2. 1 Japanese Units Identified by SWPA in the Southwest Pacific, November 1, 1942 2.2

50

U.S. Army Intelligence Estimate of Japanese Forces in the Southwest Pacific, December 31, 1942

58

3.1

ULTRA-Identified Japanese Air Units at Wewak, August 1943

84

4. 1

Estimated and Actual Japanese Ground Order of Battle, Admiralty Islands, January 1944

103

Actual and Estimated Japanese Ground Order of Battle, Wakde-Sarmi, May 1944

132

Actual and Estimated Japanese Ground Order of Battle, Biak Island, May 1944

136

5.1 5.2

Illustrations and Tables

6. 1 Estimated and Actual Japanese Ground Order of Battle, Philippine Islands, October 10, 1944 6.2 7.1

ix

159

Estimated and Actual Japanese Ground Order of Battle, Leyte-Samar-Masabate, October 1944

167

SWPA, G-2, and Sixth Army, G-2, Estimated Japanese Ground Order of Battle, Luzon, Compared with Actual Japanese Strength, December 1944

182

7.2 SWPA, G-2, Estimated Japanese Ground Order of Battle, Luzon, December 1, 1944

183

SWPA, G-2, Estimated Japanese Ground Order of Battle, Luzon, December 15, 1944

184

7.4 SWPA, G-2, Estimate~ Japanese Ground Order of Battle, Luzon, December 31, 1944

185

7.3

8.1

ULTRA-Estimated and Actual Japanese Ground Order of Battle, Kyushu, July 1945

220

Preface

In this book I assess the relationship between special intelligence and the campaigns of General Douglas MacArthur in the Pacific. During World War n, special intelligence, commonly referred to as ULTRA today, meant information obtained through monitoring, intercepting, and decoding enemy radio communications. 1 The British used the code word ULTRA from rnid-1940 to alert the initiated that special intelligence was the source of what they were reading.2 Americans in the North African and European theaters adopted the British intelligence practice and this code word. In the Pacific and Southeast Asia, no uniform policies governed the use and distribution of special intelligence, and ULTRA as a code word did not gain currency in the Pacific until March 1944. For reasons of clarity and simplicity, I use the terms "special intelligence" and "ULTRA" interchangeably.

The task I have set for myself is to do for ULTRA in the Pacific what Ralph Bennett did for ULTRA in Europe-to analyze its significance for military operations . 3 I focus on ULTRA, decrypted radio intercepts of Japanese military traffic , in one theater of operations, MacArthur's Southwest Pacific theater. I treat only in passing the well-known American efforts (MAGIC) that penetrated Japanese diplomatic codes. The triumphs of U.S. Navy cryptanalysis receive attention only as they relate to MacArthur's operations. The comprehensive story of the U .S. Navy's success against Imperial Japanese Navy codes still awaits an author. My goal is to add the ULTRA dimension to MacArthur's campaigns in New Guinea and the Philippine Islands . .

When Japanese carrier aircraft attacked the American naval base at Pearl Ha~ ­ bor, Hawaii, on December 7,1941, the U.S. Army was unable to decrypt a single Imperial Army message. Not until September 1943 did American codebreakers 611 read their firstJapanese army message. By February 1944, however, U.S . analysts .5 were deciphering more than twenty thousand Japanese army messages per month

xii

Preface

This remarkable achievement and its effects on MacArthur's campaigns form the core of this book.

The labor that preceded the break into the Japanese army codes is also important, because that' 'campaign" established parameters for the flood of information U.S. Army intelligence exploited in 1944 and 1945. Nevertheless, the focus here is on the application of ULTRA to a military campaign, not on the techniques of cracking codes and ciphers. Technical information appears solely for illustrative purposes, and any purist will object to my use of the words "code" and "cipher" as synonyms. Throughout, I pose three fundamental questions: What did American or Allied commanders know about their Jap~nese counterparts' capabilities?

When did they find out? And what did they do as a consequence? Answers to these questions often remain vague because ULTRA cause and operational effect usually cannot be fully documented. The sensitive nature of intelligence from deciphered Japanese radio messages precluded extensive note taking and recorded minutes during planning or decisionmaking sessions. Nevertheless, sufficient circumstantial and limited documentary evidence does exist to permit logical inferences about the influence of ULTRA on MacArthur's operations.

MacAtlb3lI's J!I TRA unjt, Central Bureall.,...l.ÂĽas born and matured during the Pacific war. It originated from a cadre of codebreakers brought out of the Philippine Islands in ea'rty lEJ42, supplemented by a handful of crypgnalysts from Washington. From those humble beginnings, Central Bureau developed the capabilitytOread the highest-level Japanese army secret commurucatIons_and evolved intoMaCArthur's personal and independent cryptologic organization. Much has been made of the frictIOn that existed between Central Bureau, the War Department in Washington, and the U.S. Navy's signal intelligence organization; however, overemphasizing this aspect diminishes an appreciation of the remarkable accomplishment of MacArthur's people, of the degree of cooperation, and of the exchange of ULTRA intelligence among the three parties.

Any examination of MacArthur's ULTRA must describe, however briefly, the state of the U.S. Army cryptanalytic arts in the years preceding Pearl Harbor.

Thus in Chapter 1, I discuss the complex Imperial Japanese Army codes and summarize the American army and navy signal intelligence efforts in East Asia in early 1941. I introduce key personalities in MacArthur's headquarters and describe the origins and evolution of Central Bureau from 1942 to 1945. Finally, I analyze the relationship of Central Bureau to MacArthur's theater intelligence services, the War Department, and the U.S. Navy.

In Chapter 2, I examine ULTRA in MacArthur's theater of operations in 1942. I highlight the role of intelligence in the Papua New Guinea campaign. The progress of ULTRA during 1943, particularly its use in the Battle of the Bismarck Sea and the reduction of the Japanese fortress at Rabaul, forms the centerpiece of Chapter 3. MacArthur's most spectacular use of ULTRA, its role in the plan and

Preface

xiii

execution of his leap to Hollandia, Netherlands New Guinea, is dealt with in Chapter 4. In Chapter 5, I examine MacArthur's drive into western New Guinea and scrutinize the claims made for ULTRA during the Aitape operation in NorthEast New Guinea. In chapters 6 and 7 , I offer an analysis of ULTRA intelligence and MacArthur's operations on Leyte and Luzon, Philippines. In Chapter 8, I compare the uLTRA-derived Japanese order of battle for the defense of the Japanese home islands in 1945 with the actual Japanese deployments. ULTRA'S role in this case was more than academic. ULTRA monitored the massive Japanese mobilization for the defense of the home islands, and this detailed knowledge of Japanese preparations, in turn, may have contributed greatly to the decision to use the atomic bomb . In the concluding chapter I assess MacArthur's codebreakers and the general's use of ULTRA. As British historian and former intelligence officer Peter Calvocoressi has observed, World War n featured many ways to gather intelligence, but only ULTRA was "prompt and authentic ."4 However, the intercepted and decrypted message alone was merely an impressive display of the technical craft of codebreaking.

Intelligence analysts provided a "context and background" that gave the intercepted message significance without which the decrypted information could not be fully exploited. S Context did not come overnight. It resulted from a labor-intensive recording, organizing, analyzing , and filing of thousands of seemingly inconsequential tidbits of information that, much like a jigsaw puzzle, only made sense when fitted together.

For instance, if unit X at Singapore becomes associated with unit Y in the Palaus, which , in tum, transships supplies and reinforcements to Rabaul, New Britain, then perhaps unit X will appear shortly at Rabaul. If one knows that the Shipping Headquarters in Manila has secretly announced that the former head of Army Transport Services has been appointed to command Thirty- Fifth Army in the Philippines, then Lieutenant General Suzuki Sosaku has just taken command of a previously unidentified army in the Philippines. 6 The same associations suggested the further possibility of additional Japanese forces, heretofore unsuspected, augmenting already identified formations in the Philippines. Analysts then had to determine the implications of this intelligence. Did the Japanese now have two separate army commands in the islands? If so, what did this fact portend?

Were more reinforcements en route? Each answer was another small solution to the overall mystery.

It took time to organize the outlines of the puzzle, connect similar pieces of ULTRA within the framework, and finally assemble the discoveries in a coherent manner that revealed the otherwise fragmented picture of Japanese deployments.

ULTRA was the key to the solution because it provided accurate data based on discussions among Japanese units . And, in the vast Pacific region, ULTRA uniquely provided impeccable intelligence about Japanese forces hundreds or even

xiv

Preface

thousands of miles away. Without ULTRA, great distances shrouded Japanese units behind an impenetrable security barrier. Furthermore, by early 1944 in both Asia and Europe, intercepted Japanese and German messages could be read with celerity-within hours of the time they were put on the air-and the enormous advantages ULTRA bestowed are perceived as self-evident. 7 It was not that simple in practice. As complex as it was, deciphering enemy radio communications was only the first step in a larger process designed to translate uLTRA-derived knowledge about one's opponent into action while simultaneously concealing from him that his secret communications were being deciphered. The translated decryption passed to commanders or intelligence specialists, who evaluated and decided its significance. ULTRA then had to be disseminated to field commanders, who determined how this new intelligence modified existing plans and deployments. The chief story in this book is how MacArthur and his commanders used ULTRA.

Many people in Japan and the United States generously assisted my research for this book, which began several years ago at Fort Leavenworth, Kansas .

The staff of the Military History Department, National Institute for Defense Studies, Tokyo, allowed me access to their unique archive of World War n documents . Professor Takahashi Hisashi was always helpful, as were his colleagues Professor Hatano Sumio, now at Tsukuba University, and Dr. Akagi Kanji, now at Keio University. Professor Akagi was particularly helpful by pointing out or sending me pertinent articles about military intelligence in Japan. In the United States, Thaddeus Ohta of the Japan Section, Library of Congress, was unfailingly considerate in helping me locate Japanese language books and periodicals .

Eugene Carvalho, director of the East Asian Library, University of Kansas, Lawrence, made the extensive collection of Japanese language materials on World War n housed there available to me and also took time from his busy schedule in Japan to secure otherwise unobtainable books and magazines for this study.

The primary sources in English that I used for this book are found in Record Group 457, U .S. National Archives and Records Administration, Washington, D.C. There I relied on John Taylor's expert advice and guidance for more than a decade . The National Security Agency (NSA), Fort Meade, Maryland, has been offering these documents to the Archives since the mid-1970s, and I have benefited over the years from the knowledge and first-hand experience of several NSA historians who prefer anonymity. Staff members at the Washington National Records Center, Suitland, Maryland, helped me through the massive collection of World War n unit records .

Edward Boone and Jeffery Acosta made my visits to the MacArthur Memorial Bureau of Archives, Norfolk, Virginia, both productive and enjoyable. Mr. Boone

Preface

xv

always discovered new leads that helped me clarify my thinking about the war in the Southwest Pacific. I had the good fortune to work with the excellent staff at the U.S. Army Military History Institute, Carlisle Barracks, Pennsylvania, from 1983 to 1987. At the risk of slighting some, I must thank Louise Arnold, Katherine Davis, Nancy Gilbert, David Keough, John Slonaker, Dr. Richard J. Sommers, Dennis Vetock, Michael Winey, Randy Hackenburg, and Lieutenant Colonel Martin Andresen for their assistance. At the U. S. Army Center of Military History, Washington, D.C., the historical resources staff-Hannah Zeidlik, Jim Knight, Geri Harcarik, and Steve Hardyman-were also helpful. I am also indebted to Michael Briggs and Michele McTighe Kendall of the University Press of Kansas.

I am grateful to Dr. Abraham Sinkov, Taro Yoshihashi, and Joseph E. Richard for sharing their first-hand experiences with me. Fellow historians Louis Allen, Robert Berlin, Carl Boyd, Martin Blumenson, John Carland, Ray Callahan, Harold Deutsch, Jack Finnegan, Colonel David Glantz, Michael!. Handel, William Leary, Ray Skates, Roger Spiller, and Theodore Wilson in one way or another encouraged me to complete this book. My wife, Kazuko, and daughter, Rika, deserve thanks for their support and understanding during this project.

Finally, I am indebted to Dr. Stanley L. Falk for his patience in reading several earlier versions of the manuscript. Without his constructive criticism, insights, and unparalleled knowledge of the war in the Southwest Pacific, I could not have written this book. The opinions and interpretations herein are, of course, my own.

So too are any errors.

Index

Adachi Hatazo, 53, 54, 79, 91, 94, 96, 112, 121, 143, 204: and Aitape attack, 123-124, 133, 143-144; and Bismarck Sea debacle, 71; and defense of Lae, 67, 85; at Finschhafen, 85, 87; personality, 67; and plan to ambush Allies at Hansa Bay, 97, 116,233 Admiralty Islands, 86, 96, 98, 127, 137, 223, 228, 230, 235: Allied air raids on, 98-99; Japanese defenses in, 99-100; Japanese reaction to loss of, 112; Kenney proposes seizure of, 99; strategic value of, 98, 121; ULTRA reports on, 97, 101-104 Aitape, North-East New Guinea, xiii, 56, 110, 111, 115, 118, 133: Allied operations, 119-120, 147-l5l Aiyo Maru (ship), 70 Akatsuki, 38-39, 59 . See also Japan, army Akin , Spencer B.,13,14,16, 23 , 27, 62 , 228: and Admiralties, 101; and Aitape, 147, 149; differences with Signal Intelligence Service, 28 , 31; as director of Central Bureau, 19-21, 26-28, 30; and Hollandia, 115; and Japanese Army Water Transport Code, 75-76; personality,18; prewar career, 9-11 ; relationship with Clarke, 30; relationship with special security officers, 28-29; relationship with Willoughby, 20-21 Akitsu Maru (ship), 76 Alamo Force. See U.S. Army, Sixth Army Alamo Scouts, 87,141-142 Albacore (ship), 55 Allied Air Forces, 16 Allied Intelligence Bureau (AlB), 54, 91, 108 Allied Land Forces, 16,78 Allied Naval Forces, 16, 78

Allied Translator and Interpreter Section (ATIS), 21, 73 Alphabetical List of Japanese Army Officers .

73,216 Ambon, Netherlands East Indies, 82 American Black Chamber, The (Yardley), 8 Anami Korechika, 132-133: and Aitape attack, 144; estimate of Allied situation, 113-114; personality, 124 Arawe, New Britain, 90, 100 Argonaut (submarine), 65-66 Arlington Hall Station, Arlington, Va., 6, 28, 130, 207: and Aitape, 120; breaks Japanese address code, 38; breaks Japanese Army Water Transport Code, 62, 75-76; breaks Japanese military attache code, 62, 77; evaluation of (1942), 57, 59; exchanges data with Central Bureau, 20-21, 23, 25, 38, 75, 92-93; and Kyushu, 215; mission, 21; and Philippines, 159; and Wewak Convoy Number 21, 107. See also Central Bureau; Signal Intelligence Service; Signal Security Agency Army Code Book (Rikugun angosho). See under Japan, military codes Army-Navy Central Agreement: March 1943, 72; September 1943, 86-87 Army Water Transport Code. See under Japan, military codes Ascot Park, Brisbane, Australia, 25-26 Atomic bomb, xiii, 201, 219: historical controversy over, 204; ULTRA influence in decision to use, 219, 222; ULTRA reports of destructive effect, 223-224 Australian Army: Australian Special Wireless Group, 20; 7th Infantry Division, 63; 9th 283

284

Index

Australian Army (Continued) Infantry Division, 88, 91; 18th Infantry Brigade, 45

Japanese landing at, 169-172; description, 171 Carpender, Arthur S., 37,78 CARTWHEEL, 78-79, 94-95 CAST (U.S. Navy Decryption Center, PhilipBallale, ShortIand Islands, 73 pines), II, 93 Barb (submarine), 156 Casualties, Allied: Aitape, 150; Buna, 62; CorBarbey, Daniel E., 78-79, 124, 129: and Admiralties operation, 99; and Allied landing regidor, 199; during 1943, 95; hypothetical at HoUandia, 117-118; concerned about losses on Kyushu, 218-219; Leyte, 178; Biak, 136-137 Leyte Gulf, 161; Luzon, 200-201; Opera¡Bataan, Luzon, Philippines, 15, 16, 18, 32 tion I, 73; Wakde-Sarmi, 134 Bataan Gang, 16-18 Casualties, Japanese: Aitape, 150; Arawe, 91; Bena-Bena, North-East New Guinea, 82, 84 Bismarck Sea, 71; Buna, 93; CARTWHEEL, Bennett, Ralph, xi 95; Finschhafen, 88; hypothetical losses Biak Island, Netherlands East Indies, 119, 134, on Kyushu, 218-219; Leyte, 128; Leyte Gulf, 161; Luzon, 200-201; Operation I, 151, 204, 223, 228: Central Bureau esti73; TA convoys, 178; TAKE convoy, 130; mates of Japanese strength on, 135; contribution of ULTRA to Allied invasion of, Wakde-Sarmi, 133-134 Central Bureau, xii, 28, 33, 39, 46, 61, 80, 81, 137; difficulties intercepting Japanese sig96, 128, 215: nals on, 135; Japanese defensive plans for, and Aitape operation, 144-148, 150 123-124, 131, 133; Japanese expect Allies to attack, 124; KON operation, 139-141; and Admiralties operation, 98 commemorated, 226 operations on, 134-141; Willoughby's condescription (Brisbane), 25- 26 cern about potential attack by Japanese displaces during war, 25 fleet, 135-136; Willoughby's intelligence and dissemination of ULTRA, 21, 23, 25, estimates of Japanese strength on, 128, 27-28 135-137; ULTRA detects Japanese defenearly difficulties, 27, 33-34, 53, 78 sive plans for, 126 establishment of, 19-20, 32 Biard, Forrest R. ("Tex"), 92-93, 97 expansion of, 25 Bismarck Sea, Battle of, xii, 61, 68-71, 94, as independent cryptanalytic agency, 93, 232,251 n.21: MacArthur's version of, 106; 226-227 ULTRA detects planned convoy, 68-70 intelligence about Buna, 41 Bissell, Clayton, 30-31 intelligence about Biak, 135 Black Chamber, 8 Blarney, Thomas A., 25, 28: as commander in intelligence about Port Moresby, 40 chief, Allied Land Forces, 16; and defense intercept process, 21-22, 26 limited effectiveness in 1942, 57, 59 of Port Moresby, 40; and Lae operation, mission, 20, 33 78-79, 85; personality, 18 Bletchley Park, England, 26 organization of, 26, 58 Boise (ship), 193 relations with Arlington Hall, 30,92-93 Booth, H. Roy, 26 relations with FRUMEL, 23-24 Bougainville, Solomon Islands, 90, 94 relations with Willoughby, 21 Breakneck Ridge, Leyte, Philippines, 173-174 recovers Japanese codebooks: at Aitape, 120; Brett, George H., 36 at HoUandia, 115; at Sio, 92-93, 226 Brisbane, Australia, 25, 27, 58, 110 reorganizations, 25, 28 British Far East Combined Bureau, New solves Japanese Army Water Transport Code, 62, 75-76,106, 183-184 Delhi, India, 38 solves new key register, 131 Brown, Harold W., 12, 13, 20, 26 solves three-digit code, 2, 33-34, 52, 59, Buna, Papua New Guinea, 39,40,45,67,143, 135, 149, 151, 172, 186, 227, 230 145, 146, 223, 232: casualties, 62-63; opunco~ers Japanese buildup on Kyushu, 207 erations, 41-48, 51-53, 57; ULTRA reports use of mM equipment, 27 on, 53-54, 57; Willoughby's intelligence and War Department special security ofestimates of Japanese strength in, 40-44 ficers,28 warns of Lae convoy, 64 Calvocoressi, Peter, xiii Carigara Bay, Luzon, Philippines, 167, 173, works on Japanese army codebooks, 92-93, 226 174, 228, 247: Allied concern over

Index Chamberlin, Stephen J., 16, 17, 91, 134, 157: and Admiralties operation, 99; and Buna, 41; dismisses plan to bypass Hansa Bay, 98; and Hollandia deception, 116; personality, 18; relations with Willoughby, 23 Chicago Tribune , 43 Ciphers, xii: defined, 43 . See also Japan, military codes Clarke, Carter w. , 28- 29 Clark Field, Luzon, Philippines, 186, 189, 194, 195,196-197,198 Coastwatchers, 54, 72, 91, 108 Code and Cipher Section, 8, 9 Codes, xii: defined, I. See also Japan, military codes Combined Chiefs of Staff, 32: approve bypass of Rabaul, 95; approve RENO III, 96 Combined Operational Intelligence Centre (COlC), 24, 27, 28 Commander, Submarine Force Pacific, Hawaii (COMSUBPAC), 56, 66, HlO, 106 Convoys : HI 81, 176, 184; Hollandia Number 6, 106-107; MI II, 156; Number 81,61,69-71,93; TA, 168, 169, 170178; TAKE , 129-131, 143, 151 , 232-233, 235; Wewak Number 19, 106; Wewak Number 20, 106; Wewak Number 21 , 110 Coral Sea, Battle of the, 33, 34, 36 CORONET , 203, 222 Corregidor Island, Luzon, Philippines, 10, 11, 14-15 , 199-200 Craig, Malin, 9 Daigen Maru (ship), 106 Daily Intelligence Summary (DIS) , 23, 24, 70 Darwin, Australia, 74, 83 Davao, Philippines, 2, 4, 5, 40, 48, 128- 129, 139- 141, 153 Denmark Maru (ship) , 100 Director of Naval Intelligence, Seventh Fleet, 24 Doe, Jens A., 120 Domei (news agency), 206 Driniumor River, North-East New Guinea, 143, 145-149, 204, 223, 230, 235: battle at, 150 Drum (submarine), 56 Eastern Solomons, Battle of the, 46 Eddleman, Clyde D., 186-187 , 193, 260 n .28 Eguchi Seizuke, 196 Eichelberger, Robert L. , 16, 118, 124-125 , 138, 258 n.59 Eichi Maru (ship) , 156 Enterprise (ship), 46 Etamin (ship), 120 Exaggerated battle claims: by MacArthur and

285

Kenney, 71-72, 89-90; by Japanese pilots, 73, 83, 89, 166, 168 Ezaki Yoshio , 102-103 Fabian, Rudolph J., 37 , 43 , 89: contribution at Milne Bay, 47; and Number 81 Convoy, 68-69; and establishment of FRUMEL, 15-16; and PURPLE Machine, 11; relations with MacArthur's headquarters, 23-24 Far East Combined Bureau, New Delhi , India, 38 Federal Communications Act (1934) , 9, 10 Fellers, Bonner, 116: and decision to bypass Hansa Bay, 97-98 Finschhafen, North-East New Guinea, 73, 78, 89: operations, 85-88 .. Fist" (transmission) technique, 58 Fort McKinley, Luzon, Philippines, 11 Fort Mills, Corregidor, Philippines, 11 Fort Stotsenburg, Luzon, Philippines, 196 Four-digit code, 1-7, 33, 59, 77, 92,101,115, 226-227 Friedman, William F., 8-10 FRUMEL (Fleet Radio Unit , Melbourne) , 15, 93 , 242-243 n .30. See also under Fabian, Rudolph J. FRUPAC (Fleet Radio Unit, Pacific), 93 Fujiwara Akira , 210 Fuso Maru (ship) , 156 Gato (submarine), 106 Geelvink Bay, Netherlands East Indies, 85, 129, 143: IGHQ plans for, 124; and KON operation, 139; as objective of RENO m, 95; strategic value of, 123, 131 Gilbert Islands, 94 Gill, William H ., 143, 147, 149 Goodenough Island, 73 Government Code and Cipher School, England , 26 Grampus (submarine), 65-66 G Section, 9 Guadalcanal, Solomon Islands, 39, 41, 44, 46, 48, 49, 63, 67, 68, 99: Japanese fleet alerted to imminent Allied operation, 45; and Operation I, 72; U.S . intercept sites on, 55 Gurnard (submarine), 130 Hall , Charles P., 229-230: and attack on Aitape , 147-149 Halmahera Islands, 95 , 131: Japanese air reinforcements on, 109; Japanese expect attack on, 142, 153; as objective of RENO V, 136; role in primary defensive zone, 124; ULTRA detects Japanese build-up on, 126, 128, 152-153

286

Index

Halsey, William F., 78, 152, 157, 161, 169, 175 Handy, Thomas T., 30 Hansa Bay, North-East New Guinea, 77-78, 97: Adachi's plans for, 97, 106, 112, 115; as MacArthur's objective, 94-96; role in Willoughby's deception plan, 116-117; ULTRA reveals Japanese trap on, 97, 233 Hart, Thomas C ., 11 Hata Hikosaburo, 168, 172 Hawaii Conference, 153 HI 81. See under Convoys Hirohito, emperor of Japan, 66, 73, 87: concerned about civilian morale, 191; and homeland defense, 202, 211; questions Lae landing, 71; role in Japanese surrender revealed by ULTRA, 225; and Tominaga appointment, 160 Hiroshima, Japan, 219: ULTRA description of atomic attack on, 223-224 Hollandia, Netherlands East Indies, xiii, 23, 25, 55, 134, 143, 223, 228, 230, 233, 235: airfields destroyed, 108-112; Allied discovery of Japanese code materials at, 120; conferences at, 129; ground operations, 116-121; as Japanese base, 80, 82-83; Japanese reaction to attack on, 124; as RENO ill objective, 95; ULTRA basis for MacArthur's plan to attack, 97, 98, 104105, 115; ULTRA role in interdiction of convoy bound for, 106-108 Hollandia Convoy Number 6. See under Convoys Horii Tomitaro, 40, 43, 51 Horizontal communications, 33-34 Hurt, John, 9 Imamura Hitoshi, 63, 91, 95 attempts to reinforce Admiralties, 99-101 and defensive plans for 1943, 63-64: revealed by ULTRA, 97, 101-102 and Number 81 Convoy, 66-67 personality, 63 Imperial General Headquarters (IGHQ), 1,2, 4, 5, 52, 56, 66, 106, 139: and Admiralties, 99-101; and attack on Port Moresby, 39-40; and defense of New Guinea, 48, 55,79,86,87,108; and early wartime euphoria, 32; estimate of Japanese military situation (1943), 86-87; and Guadalcanal, 45,63; and Hollandia, 109-110, 117, 124; and homeland defense, 203, 208, 210-211, 213,216-218; and kamikaze tactics, 164; and Lae convoy, 67; and Leyte assessment, 163, 168, 176, 177-178; and Luzon, 200; and Philippines, 176; plans SHO operations, 154, 160; redefines defense zone, 86, 131; and Wewak convoys, 107

Imperial Rescript (August 14, 1945), 225 Inada Masazumi, 118 Itabana Giichi, 68, 118 Iwabuchi Sanji, 189-190, 197-198, 199 Jack (submarine), 129 Japan, army -General Armies First General Army, 206 General Army Air Command, 206, 209, 224 Kwantung Army, 7 Second General Army, 206, 208, 224 Southern Army, 4, 52, 108, 153, 184, 206, 225: defensive strategy detected in ULTRA, 131, 173; and Leyte reinforcements, 166, 176-177, 178; Luzon as decisive battle, 155, 191 -Area Armies First, 160 Second, 5, 7, 8: at Aitape, 144, 146; on Biak, 137; controls Eighteenth Army, 112; counterattacks on Hollandia, 110, 124; defenses in western New Guinea, 123; defensive strategy detected: in ULTRA, 113, 131, 142; and KON operation, 140 Third, 7 Eighth, 7, 64, 66, 94: and Admiralties, 100-102, 104; and Battle of Bismarck Sea, 71; and creation of special intelligence units, 82; defensive strategy detected in ULTRA, 97,106; formation, 55-56; on Hollandia, 108; New Guinea strategy, 63-64, 66-67; suspends Wewak convoys, 107; warns of possible Allied attack along New Guinea coast, 117 Fourteenth, Ci4, 159, 161: and defense of Manila, 188-189; on Leyte, 166, 173, 191; on Luzon, 193, 198 Sixteenth, 204, 207, 208, 214, 215, 219, 222 -Armies Second, 123, 124, 127 Fourteenth, 154 Seventeenth, 40, 44, 48, 52-53, 55, 73 Eighteenth, 39, 55, 67, 74, 99: and attack on Aitape, 143-151; and plans to ambush Allies at Hansa Bay, 115-116; believes Allied deception tactics, 116-117; bypassed and isolated from resupply, 108, 112, 123; defensive plans for, 94; defensive strategy detected in ULTRA, 97, 106, 113; frrst detected in ULTRA, 53; and Hollandia operations, 105, 112-120; and Lae convoy, 64, 66-67; and poor code security, 121; role in New Guinea strategy, 63, 66 Thirty-Fifth, xiii: defends Leyte, 160, 167, 170; detected in ULTRA, 154, 157 Fortieth, 211, 215, 219

Index Fifty-Sixth, 208, 211, 215, 219 Fifty-Seventh, 207, 215 Fifty-eighth, 207, 215 -Brigades 4th Armored, 215 5th Armored, 215 6th Armored, 215, 216 -Divisions 1st Armored, 208 2d Armored, 156-157, 181, 182, 192-193, 194, 199 -Infantry 1st, 160, 173, 175, 178, 181, 194: Allied uncertainty of location, 170-171; arrives in Leyte, 168-169; fights in battle on Breakneck Ridge, 174; fmt appears in military attache message, 172; fortifies heights over Carigara Bay, 171-172; and ULTRA, 169, 171 3d,57 4th,57 5th, 55, 57 6th Depot, 204 7th,219 8th, 156, 177, 181, 195 9th, 194 10th, 182, 184, 199: fmt detected in ULTRA, 184-185; losses in submarine attacks, 184; unlocated by Allies, 194 11th, 194 12th, 182, 184 14th,7 16th, 49, 244, 252, 253, 256, 265: first detected in ULTRA, 232-233; on Leyte, 166-167,172-174; losses revealed in ULTRA, 181 17th, 87, 90, 102 19th, 185, 192, 193, 196 20th, 34, 57, 91, 97, 112: at Aitape, 145148; and Finschhafen operations, 87-88, 90; and loss of code library, 62, 92; moves to Madang, 66, 68; moves undetected to Wewak, 66; radio net with subordinate units, 34; and Sio operations, 92; Willoughby estimates strength of (May 1943), 77 21st, 57 23d, 176, 183-184, 232: losses in submarine attack, 176, 184; as part of Japanese defense on Luzon, 192-193, 195, 199 25th, 203, 207, 208, 217, 218 26th, 168-169, 172-173, 181, 182: losses in air attacks, 175-176; losses in submarine attacks, 156; transfer to Philippines detected in ULTRA, 154 28th, 154 29th,7 30th, 153, 154, 157, 170, 172, 173, 181

287

32d, 124: aboard TAKE convoy, 129-130 35th, 124, 141, 142, 143: aboard TAKE convoy, 129-130 36th, 115, 116, 118, 141: on Biak, 123; and Sarmi operations, 124, 127, 128, 131, 133, 134, 135; and ULTRA, 126 38th, 49,101-102 4Oth,77 41st, 57, 68, 88, 91: at Aitape, 145-148; suspected at Wewak, 77; and ULTRA, 97, 112 48th,49 51st, 48,57,61,64,74,77,79,85,89,106, 232: aboard Lae convoy, 67-68; losses in Bismarck Sea, 71-72; ordered to Lae, 101; and ULTRA, 97 54th,96-97 56th Depot, 204 57th, 203, 204, 206, 207, 218 65th,49 77th, 209, 217 86th, 204, 207, 217 100th, 154, 181 102d, 154, 166, 172, 181 103d, 154, 181 105th, 154, 181 115th, 158 145th,219 146th, 203, 215, 217, 218 154th, 203, 214, 217, 218 156th, 203, 215, 217, 218 203d,215 206th, 208, 214, 218, 219 212th, 208, 212, 214, 218 216th, 208, 218, 219 303d, 211, 214, 218, 219 312d, 211, 219 351st, 211, 219 Guards, 49-50, 57, 161 -Independent Mixed Brigades 21st, 50, 53 54th, 154 55th, 154 58th, 182, 192, 193, 195, 199 61st, 193 65th, 50 68th, 168, 177 98th,218 118th, 211 122d, 211, 215 124th,218 125th, 207, 211, 216, 217, 218 126th, 211, 215 -Regiments 18th Armored, 204 30th Armored, 214 37th Armored, 214, 215 40th Armored, 214, 215

288

Index

Japan, Army Regiments (Continued) 1st Independent Mixed, 100, 101, 102 18th Independent Mixed, 154 5th Infantry, 177 31st Infantry, 156 34th Infantry, 172 41st Infantry, 43, 167 57th Infantry, 172 64th Infantry, 184 66th Infantry: and Admiralties, 99-100; as victim of submarine attack, 100, 106 72d Infantry, 176, 184 78th Infantry, 34, 77, 112, 150 79th Infantry, 34 80th Infantry, 34, 85 102d Infantry, 64, 77 115th Infantry, 74, 89: losses in Bismarck Sea, 71 l44thInfantry,43,52 219th Infantry, 141-142 222d Infantry, 141: on Biak, 123, 135 223d Infantry, 123, 127, 134 224th Infantry, 123, 127, 133, 134 229th Infantry, 101, 103, 104 -Shipping units Army Shipping Headquarters, Hiroshima, 152 Shipping Force, 74 1st Shipping Group, 38 1st Shipping Engineer Group, 86 8th Shipping Engineer Regiment, 87 1st Water Transport Command, 74 2d Water Transport Command, 74 3d Water Transport Command, 74, 186 Shipping Command, 62, 74 -Miscellaneous units Akatsuki Force, 49 2943 (Shipping Group 1), 38 6168 (units of Shipping Command, Moji), 39 6169 (Shipping Command Group 2), 39 6170 (Shipping Engineer Regiment 1), 39 6433 (Anchorage Unit 45), 38 Amphibious brigades: 2d, 139, 153; 3d, 206, 207,217 1st Artillery Command, 214 1st Field Replacement Headquarters, 186 4th Artillery Command, 219 19th Pioneer Unit, 55 24th Special Base Force, 55 40th Field Road Construction Unit, 77 51st Transport Regiment, 99, 101, 102 61st Field Antiaircraft Battalion, 77 KEMBU Group, 189, 193 SHIMBU Group, 189, 193, 194, 197, 199 SHOBU Group, 189, 192, 199 South Seas Detachment, 40, 43, 48, 49 Takaya Detachment, 196

Takayama Detachment, 196 Japan, army air force -Armies First Air, 222 Fourth Air, 83, 98, 112-113, 118: attacked at Hollandia, 108-110; concentration at Hollandia detected in ULTRA, 108-109; on Leyte, 155, 160, 162; on Luzon, 186, 192, 196 Fifth Air, 222 Sixth Air, 211, 222 -Brigades 8th Air, 109 9th Air, 86 12th Air, 70, 81 14th Air, 81 -Divisions 2d Air, 70, 81 4th Air, 153, 155 6th Air, 55-56, 64, 66: at Arawe, 91; and Bismarck Sea, 68, 70; and Hollandia, 118; and Lae convoy, 66; on Luzon, 186; at Wewak,84 7th Air, 81, 84, 128 -Regiments 7th Air, 86 10th Air, 83 11th Air, 56 13th Air, 84, 86 14th Air, 81, 82 24th Air, 80, 82, 86 33<1 Air, 109 34th Air, 109 45th Air, 56, 80, 82 58th Air, 83 59th Air, 84, 86 60th Air, 107 61st Air, 80, 82, 86, 109 63d Air, 98 68th Air, 81 75th Air, 82-83, 107, 109, 119 77th Air, 107 78th Air, 81, 83, 84 -Miscellaneous units 1st Air Squadron, 56 4th Air Intelligence Detachment, 82, 84 2d Air Communications Group, 186 76th Independent Air Squadron, 56, 82 Japan, Foreign Ministry codes, 10-11, 15, 76-77, 175, 180, 193, 195, 203-204, 214, 227. See also PURPLE Machine Japan, homeland defense, 206-209: mobilization for, 202-203, 211; planning for, 213-214 Japan, military codes address code, 37-38 army air force codes, 241, 264

Index Army Code Book, 1-2,4,6,195,226-227, 266 n.3 Army Water Transport Code, 62, 152, 154, 180,226,232: and Leyte, 176-177; solution of, 74-75; and TAKE convoy, 129131; value of, 76, 106-107 call signs, 37 changes to key register, 37, 43, 53-54, 66, 73, 76, 115, 120, 151, 195, 200, 226-227, 257 n.50 code books lost: at Aitape, 120; in Philippines, 201; at Sio, 92, 226 compromises unsuspected, 53-54, 73, 76, 107-108,130-131,140 discriminants, 2 example of, 4-6 explanation of, 1-2 four-digit code, 1-7, 33, 59, 77, 92,101, 115, 226- 227 key register, 1-2,7 military attache code. See Japan, military attache codes quantity of code messages, 52-53 three-digit code, 2, 33, 52, 172, 186, 227, 230: invulnerability of, 59, 149, 151 Japan, military and naval intelligence: and Admiralties, 102; and anticipated Allied invasion of Kyushu, 207; attitudes toward, 82, 142; and Biak, 124, 139, 141; and Hollandia, 116, 117, 118; and Leyte, 161; and Luzon, 192; and prewar codebreaking, 13; and radio deception, 169; special intelligence, 82; and Wakde, 133; warns of Allied operation (1942), 44-45 Japan, military attache codes, 76 Allied solution of, 61-62 value to Allies, 61-62: on Leyte, 172-173; on Luzon, 195 Japan, navy Combined Fleet, 128-129, 139, 140, 141, 161, 166, 168 Combined Naval Forces, 207 First Mobile Fleet, 139 First Striking Fleet, 158 Second Fleet, 161 Third Fleet, 40, 72, 161 Eighth Fleet, 47, 64 Southeast Area Fleet, 99-100 Southern Expeditionary Fleet, 141 Southwest Area Fleet, 95, 116, 139, 167, 168, 189 1st Battleship Division, 141 1st Carrier Division, 89-90 1st Combined Signal Unit, 169 3d Kure Special Naval Landing Force, 47 5th Kure Special Naval Landing Force, 47

289

5th Sasebo Special Naval Landing Force, 40-41,51 6th South Seas Detachment, 101, 107 8th Base Force, 41 14th Construction Detachment, 40, 43 15th Construction Battalion, 43 16th Cruiser Division, 139-140 18th Cruiser Division: and attack on Milne Bay, 47; and Buna operation, 41-42 19th Naval Guard Division, 139 28th Base Force, 141 31st Special Base Force, 189-190 Japan, naval air units First Naval Air Fleet, 155, 162 Second Naval Air Fleet, 162-163 Fifth Naval Air Fleet, 213 Eleventh Naval Air Fleet, 55, 91: in Bismarck Sea, 68, 70; and Lae convoy, 64-65; and Yamamoto shootdown, 72-73 12th Air Flotilla, 209 13th Air Flotilla, 212 23d Air Flotilla, 128 25th Air Flotilla, 89 26th Air Flotilla, 89 72d Air Flotilla, 212 Jinyo (ship), 176 IN-25 (naval operational code), 13 Joint Chiefs of Staff (JCS), 178, 192: appoint MacArthur commander in chief, SWPA, 32; argue for bypassing Philippines, 148149, 152-154, 157-158; and Hollandia, 105; and invasion of Japan, 203, 209-210; and Luzon, 180; MacArthur appeals for resources, 48; order dual axes of attack on Philippines, 96; reassess strategy, 104-105 Joint Intelligence Center, Pacific Ocean Area (JlCPOA), 167 J Section, 9 Kamikazes, 160, 187: first appearance of, 167; and homeland defense, 206, 209, 211, 212-213; on Leyte, 163; on Luzon, 192 Kami Shigetoku, 189 Kanga Force, 40, 63 Kanto Plain, 202-203 Kashii Maru (ship), 175 Kataoka Tadasu, 174 Kawahigashi Moritoshi, 150 Kayo Maru (ship), 106 Kenney, George C., 61, 96, 116, 118, 119, 153, 157,229-230,232 and Admiralties, 98-99, 102 attitude regarding ULTRA, 43, 71-72, 102,232 and Biak, 141 and Buna and Milne Bay, 43, 45-47 and CARTWHEEL, 79 and convoy interdiction, 54-55, 93, 174-176

290

Index

Kenney, George (Continued) and exaggerated claims: after Battle of Bismarck Sea, 71-72; at Rabaul, 89-90 as innovator, 43 and Lae convoy, 64-65 and Leyte campaign, 163-169 and Luzon campaign, 187, 194 neutralizes Japanese airpower in New Guinea, 79-85 and use of ULTRA: in convoy warning, 67-68, 175; in planning Hollandia raids, 108-112; in Rabaul raids, 89-90; in Wewak raids, 80-85 urges seizure of Salamaua, 79; of Wakde, 126 Ken'zui Maru (ship), 184 KETSU operation, 206, 208 King, Ernest J., 180 King, MacKenzie, 158 Kinkaid, Thomas C., 96, 229, 232: and Admiralties operation, 99; and Biak, 139-141; and Leyte, 161; and Luzon, 187 Kirishima (ship), 191 Kobayashi Shujiro, 188 Koiso Kuniyaki, 191 Kokoda, Papua New Guinea, 40 KON operation, 139-141, 151,232 Kroner, Hayes A., 36 Krueger, Walter, 10, 16, 78, 229-230: and Admiralties, 99, 110-114; and Aitape, 147149; and Arawe, 90; and battle at Lone Tree Hill, 133-134, 228; and Biak, 138; deals with conflicting intelligence reports, 133-134, 151, 169-171, 200; and estimates of Japanese strength on Luzon, 180, 186; and Hansa Bay operation, 94; and Japanese 1st Division, 169, 171; and Leyte, 162, 163, 169-173; and Manila, 187, 194-195, 197-198; and Noemfoor, 134, 142; and OLYMPIC preparations, 203, 211, 217-218; personality, 78; pressured by MacArthur, 138, 149, 193, 195-196; strategy in western New Guinea, 123-124, 125, 129 Kullback, Solomon, 9, 19 Kurita Takeo, 161-162 Kuroda Shigenori, 160 Kusaka Jin'ichi, 73, 99-101 Kuzume Naoyuki, 204: and defense of Biak, 137-138, 141 Kyushu, Japan, 201, 206: air reinforcements to, 211-212; defense of, 202-203,206-207, 208; defensive strategy for, 213-214 Lae, North-East New Guinea, 37,42,63, 89, 223: as CARTWHEEL objective, 78-85; as Japanese stronghold, 66, 78; and Number 81 Convoy, 67-69

Lae convoy (January 1943), 61 Lateral communications, 33-34 Layton, Edwin T., 36-37 Leahy, William D., 210 Lexington (ship), 36 Leyte, Philippines, xii, 25, 29, 135, 153, 154, 180, 182, 204, 223, 228: Allied landings on, 161; Allied concern about Japanese landing at Carigara Bay, 169; Allied plans to invade, 157; battle for Breakneck Ridge, 173-174; Japanese reinforcements to, 166-169; Krueger and conflicting intelligence about, 170-171; significance of Allied victory on, 178-179; Sutherland approves invasion of, 158. See also Breakneck Ridge; Carigara Bay; Krueger, Walter; TA operation Leyte Gulf, battle for, 161-162, 167 Lingayen Gulf, Luzon, Philippines, 185, 191, 192, 194, 195, 201, 209: Sixth Army landings in, 192-193 Lone Tree Hill, battle for, 133-134, 135, 228 Los Negros, Admiralty Islands, 101, 102, 103 Luzon, Philippines, xiii, 123, 153, 180, 204, 210,223 and absence of army ULTRA after February I, 1945, 195 Allied decision to invade, 187-188 Allied debate on bypassing, 152-154, 180 capture of Japanese codebooks on, 201 estimates of Japanese strength on: by War Department, 151, 181-183; by White, 181-182, 193; by Willoughby, 181-183, 185-186, 193 Japanese defenses on, 154-155, 160, 188189, 192-193 operations, 193-200 MacArthur, Douglas, xi-xiv, 11, 18, 20-21, 26-27,32,79 and Admiralties, 99-100, 102 aggressive strategy of, 90, 94-96, 124-125, 136 and Aitape, 148 and Arawe, 90-91 assessment of, 234- 235 and atomic bomb, 219 attitude toward intelligence, 68-69, 187-188, 194,222-224 and Battle of Bismarck Sea, 68-69 and Biak, 135-139 and Buna, 41-43, 230 and CARTWHEEL, 78-79, 94-95 as commander in chief, United States Army Forces, Pacific, 203 desire to liberate Philippines, 95, 124, 148149, 181, 187, 230

Index establishes SWPA, 16 exaggerates battle claims, 71-72, 89-90 favors strategy that bypasses and isolates Japanese garrisons, 94-96 and Finschhafen, 88 forms Central Bureau, 19-20 and Germany-first strategy, 32 and Hansa Bay, 94-95 and Hawaii Conference, 153-154 and HoUandia, 104-105, 109-110 and invasion of Japan, 203 and Japanese estimate of strategy (1944), 158 and Japanese overland attack on Port Moresby, 37, 42 and Joint Chiefs of Staff, 104, 148, 152 and Lae operation, 79 and Leyte, 158, 178-179 and liberation of Manila, 191-192, 194, 198 and Luzon, 186-189 military gains to January 1944, 94 and Milne Bay, 45-47 and Nassau Bay operation, 19 personality, 19 and Philippine Campaign (1941-1942), 14-16 predictability of tactics, 86 pressures subordinates, 123, 125, 128, 149, 195, 196, 230, 234 provides casualty estimate from invasion of Kyushu , 209-210 recognizes need for fighter bases, 110 relies on naval ULTRA, 22, 24, 36, 47-49, 54,57,59 and risk taking, 121, 131, 136, 178, 230-231, 233-234 and Saidor, 91 Soviets enter into Pacific war. 210, 222 and Station 6, ll, 14-15 status of SWPA, 41, 46-47, 59, 63, 65, 69 and ULTRA: control of, 28-29; influence of on strategy, 121-122, 131, 228-229, 230, 233-234; use of, 23, 76, 104-106, 112119, 121-122; willingness to ignore, 57, 71-72, 121, 136, 154, 178, 186-187, 194, 222-223, 228-230 and Wakde-Sarmi, 124, 126-127, 129 McDilda, Marcus, 224 Mackie, Thomas R., 92-93, 97 Madang, North-East New Guinea, 55, 56, 67, 68, 70, 71, 97, 1l0: bypassing of, 112-114; as CARTWHEEL objective, 78 Maffin Bay, 133, 134, 135 MAGIC, xi, 24, 201: first use as code word, 10; prewar dissemination, 11; use in MacArthur's prewar headquarters, 11-12 MAGIC Diplomatic Summary, 24-25 Magruder, George L., 22

291

Manila, Luzon, Philippines, xiii, 4, 5, ll, 183: fighting in, 197-198; Japanese debates over defense of, 188-189; Japanese defenses at, 182, 186, 191, 195, 197; MacArthur's desire to liberate, 187, 193; ULTRA detects Japanese withdrawal from, 191, 195; White predicts tough Japanese defense of, 193; Willoughby expects delaying action by Japanese, 193 Manokwari, Netherlands East Indies, 124, 131, 142 Marianas Islands, 96, 141, 152 Marilinan, North-East New Guinea, 82, 83 Marshall, George C., 10, 20, 228, 233: acknowledges SWPA as independent decryption center, 19, 28-30; and atomic bomb, 222; concern over anticipated U.S. casualties if Japan is invaded, 209-210, 222; and Germany-first strategy, 32; and HoUandia, 104-105, 117; and invasion of Japan, 203; position in bypassing debate, 148-149, 152-154, 157-158; requests received from MacArthur, 48-49, 96-97; and ULTRA evidence of Japanese buildup in Philippines, 148-149; on value of reading Eighteenth Army codes, 121 Matsui Keiji, 85 Matsuo Yutaro, 107 Mauborgne, Joseph 0 ., 10 Mayasan Maru (ship), 176 Melbourne, Australia, 15, 16, 38, 41 as home of Central Bureau, 19, 20, 21, 25, 32 as location of FRUMEL, 15,24,37,40,64, 66,87,127. See also Fabian, Rudolph J.; FRUMEL MI-8 (branch of Military Intelligence Division, U .S. War Department), 8 MI-ll convoy. See under Convoys Midway, Battle of, 33, 40, 63, 228: Chicago Tribune reveals secret use of codebreaking, 43 Mikawa Gun'ichi, 167, 189 Milne Bay, Papua New Guinea, 40-41, 44: Operation I, 72-73; operations, 46-48; ULTRA regarding, 47 Military Intelligence Division (MID), U.S. War Department, 8, 30, 36 Military Intelligence Service (MIS), U.S. War Department, 76, 77, 107 Mindanao, Philippines, 95, 96, 123, 152-153 Mindoro, Philippines, 187-188, 191 Moemi, Netherlands East Indies, 55 Morotai Island, 135, 143, 153, 157 Morse Code, 4, 21, 58, 101 Munitions Building, Washington, D.C., 8, II Musashi (ship), 141

292

Index

MUSKETEER, 154 Muto Akira, 160-161, 188-189

Nadzab, North-East New Guinea, 61, 85, 89: Allied fighter base at, 91 Nagasaki, Japan, 224 Nakano Hidemitsu, 85, 90 Nashville (ship) , 124, 137, 157 Nassau Bay, 79 National Volunteer Corps, 213 Naval Communication Intelligence Center, Washington, D.C., 65 Naval Intelligence, Seventh Fleet, 24 New Georgia, Solomon Islands, 81, 91 New Ireland Island, 96 Nimitz, Chester w., 34, 36, 49, 94, 102, 178 , 219: and Central Pacific drive, 95-96; Joint Chiefs of Staff request views of, 104; orders MacArthur be informed of ULTRA, 37; position in bypassing debate, 148, 153-154, 157, 158, 180; supports HolIandia operation, 100, 119 Nishimura Shoji, 161 Noemfoor Island, 126, 134, 135: Allied attack on, 134, 141 Nota Maru (ship), 169 Numada Takeyo, 137 Conference, 157 Office of Naval Intelligence, Washington , D.C., 24 Ogawa Takeshi, 73-74 Okabe Tooru, 64, 66, 67 Okawachi Den'shichi, 189, 197, 199 Okinawa, Japan, 154,202, 203, 208, 209, 210-211, 213, 217 Okunia Maru (ship), 156 OLYMPIC, 203, 209-210, 211, 217, 222, 234: fictionalized accounts of, 218-219; and Japanese plan of defense, 218 Operation A, 139, 141 Operation 18, 66 Operation I, 72-73 Ormoc , Leyte, Philippines, 167: 1st Division landing at, 168-169; resupply convoys to, 169-170, 174-177; and ULTRA, 167-168 Oro Bay, Papua New Guinea, 49, 51, 72, 89 Oshima Hiroshi, 77 Owen Stanley Mountains, New Guinea, 44, 48 , 49: MacArthur discounts probability of Japanese attack through, 40 Ozawa Jisaburo, 162

OCTAGON

Pacific Fleet, Combat Intelligence Center, 37 Palau Islands, xii, 38, 39: as Japanese staging base, 48,55,64,66,77,100 Panama Canal Zone, 9

Parche (submarine), 156 Pearl Harbor, Oahu, 9, 12: conference at, 96; Japanese attack on, xi, xii; legacy of attack,217 Peto (submarine), 106 Philippine Islands . See Leyte; Luzon; Manila; Mindanao; Mindoro Picuda (submarine), 176 Port Moresby, Papua New Guinea, 34, 39, 53, 58, 72, 89, 146: Allied airfields at, 64, 67; defense of, 40; IGHQ plans overland attack on, 39-42; ULTRA warns of planned attack on, 36-37 Potsdam Declaration: Japanese emperor accepts, 225 PURPLE Machine, 10-11, 15: value of during World War II, 76-77 Q UADRANT Conference, 95 Queenfish (submarine), 176

Rabaul, New Britain, xii , xiii , 27, 32, 34, 36, 38, 39, 51, 89: and air war, 89-90, 98; as CARTWHEEL objective, 78; and convoys, 40-41, 53-54, 64; in RENO ill, 95; as staging base, 40, 41, 42, 53, 54 Ramage, Lawson P., 156 Raven, Francis A., 10 RED Machine, 10 REI operation, 188 RENO plans, 146: I, 95; II, 95; ill, 95; IV, 98; V, 123, 136, 153 Richard, Joseph E. 75, 92 Rochefort , Joseph J., 37 Roosevelt, Franklin D., 153 Rowlett, Frank, 9 Royal Australian Navy, Directorate of Intelligence, Coastwatcher Service. See Coastwatchers Ryuho (ship), 56 Saidor, North-East New Guinea, 91, 94, 100, 143 St. La (ship), 164 Saipan, Marianas Islands, 141, 154-155, 164 Sakakida, Richard M., 131. See also Convoys, TAKE

Sakonju Naomasa, 139-140 Salamaua, North-East New Guinea, 37, 40, 41 , 79, 85, 86 Sanford, Alastair W., 26, 267 n.42 San Miguel, Luzon, Philippines, 25 Sansapor, Netherlands East Indies, 135, 142143 Sarmi, Netherlands East Indies, 115, 118, 124, 138, 151: Allied intelligence about, 126127,131; operations, 132-133 Sawar, Netherlands East Indies, 100

Index Seawolf (submarine), 100

Conference, 95-96 Sherman, Frederick, 175 Sherr, Joe T., 13, 15: in Australia, 26, 33; and prewar codebreaking, 11 Shigemitsu Mamoru, 193 Shoho (ship), 36 Shokaku (ship), 36 SHO operations, 160, 161-163: described, 155; and ULTRA, 153 Signal Intelligence Service (SIS), 8-12, 75: control of overseas theaters, 28; prewar security practices, 12; and PURPLE solution, 10; redesignated Signal Security Agency, 61; relations with Central Bureau, 19, 20; relations with Station 6, 11, 14; solves Japanese message address code, 38 ; work against prewar Japanese codes, 8-10. See also Arlington Hall Station; Central Bureau; Signal Security Agency Signal Security Agency (SSA), 6-7: breaks military attache code, 76; breaks Army Water Transport Code, 75; success against Japanese army mainline code, 61 Singapore, Malaya, xiii, 15, 20, 32, 55: as Japanese naval base, 128-129 Sinkov, Abraham, 9, 18, 19, 21, 22, 25, 26, 33 , 226: and evaluation of ULTRA at Aitape, 144; and Hollandia, 115; and solution of Japanese army mainline code, 93; and solution of Japanese Army Water 'fransport Code, 75 Sio, North-East New Guinea, 62, 88, 131, 136, 328: Japanese army codebooks captured at, 92-93 Solomon Islands, 46, 51, 55: coastwatchers in, 54; Japanese attacks against, 46 Sorong, Netherlands East Indies, 124, 131: bypassed by Allies, 142, 143 Southwest Pacific Theater, General Headquarters (SWPA), 16, 21, 24, 26, 78, 143: and Aitape, 145; and Battle of Bismarck Sea, 69; and Buna, 230; and Central Bureau, 19, 22; and distribution of ULTRA, 27, 29, 31, 61, 62, 77; and estimates of Japanese strength on Luzon, 181, 186, 193, 196; and Finschhafen, 87; formation of, 16, 32-33; and Hollandia deception, 116, 119; and Kyushu, 109; and Leyte, 157, 173; and TAKE convoy, 129, 131 Southwest Pacific Theater, G-2 (Intelligence): Operational Section, 22-23; Order of Battle Section, 22, 101; Plans and Estimates Section, 23 Spadefish (submarine), 176 Special Branch, Military Intelligence Service, 29-30 SEXTANT

293

Special Intelligence. See ULTRA Special Intelligence Bulletin (Sm) , 23,.144 Special security officers (SSOs), '17, 24: treatment of in SWPA , 28-29, 228 Sprague, Thomas L., 167 Station 6, Luzon, Philippines, 11, 14-15, 21, 26: evacuated from Corregidor, 16; exchanges of data with CAST, 11; mission, 11; as nucleus of Central Bureau, 20 Steelhead (submarine), 156 Stimson, Henry L., 222 Strong, George V. , 28 Struble, A. D., 177 Submarine Force, Hawaii, 56, 66, 100, 106 Sugiyama Hajime, 160 Sutherland, Richard K., 11, 12,17,19,30, 76, 96: and Admiralties, 101-102; advises delay at Luzon, 187; and Aitape, 147; briefs Hollandia plan to Joint Chiefs of Staff, 105; and Central Bureau, 21; and Japanese attack on Port Moresby, 36; Krueger's opinion of, 16, 196; and MAGIC , 24, 25; orders invasion of Leyte, 158; personality, 16 Suzuki Sosaku, xiii, 154, 160, 170, 204 Takasu Shiro, 139 Takatsu Maru (ship), 257 TAKE convoy. See under Convoys

Tanoue Hachiro, 127 operation, 168-169, 170-178 T Attack Force, 162-164 Tawitawi Island, Netherlands East Indies, 128, 139 Tenryu (ship), 55, 232 Teramoto Noriichi, 83, 86 Terauchi Hisashi, 166, 173, 176, 191 Toem, Netherlands East Indies, 132-133, 134 Tojo Hideki, 154, 160, 161 Tominaga Kyoji, 160, 162-163, 164 Townsville, Australia, 26, 33, 58, 59 Toyoda Soemu, 139, 141, 168 Traffic analysis, 38, 48, 79, 88, 98, 115, 144, 145, 215: Australian efforts at 27, 33; defined, 33; example of, 38-39; value of Allied commanders, 37, 39 Triton (submarine), 66 Truk, Caroline Islands, 40, 55, 72, 86 Truman, Harry S ., 209, 234: and atomic bomb, 219; concerned about U.S. casualties if Japan is invaded, 210 Tsili- Tsili, North-East New Guinea. See Marilinan 2468 Code system . See Japan, military codes, Army Water Transport Code Twenty-One Henry Street, 92, 226: as Central Bureau headquarters, 26-27

TA

294

Index

Ugaki Matome, 48, 72, 141 ULTRA, 17, 18: as code word, xi, 240 n.2; concealing source of, 69-70, 107-108, 110, 144; contribution to Pacific war, xiii-xiv, 179, 228-229, 230-233; defined, xi; dissemination in SWPA, 22, 27, 228; exaggerated importance of, 234-235; influence on decision to use atomic bomb, 209, 211, 216,219-220; initial security problems in SWPA, 27, 30, 244-245 n.30; limitations of, 184-185, 229, 231; situational use of, 234; value of, 54-56, 108, 155-157, 228-229 ULTRA Intelligence Summary. See Special Intelligence Bulletin Umezu Yoshijiro, 168, 202, 206 U.S. Army -Armies Sixth, 29, 228, 230: at Aitape, 148, 149; at Biak, 138; in Carigara Bay, 170; creation of, 78; differs with SWPA estimates of Japanese strength on Luzon, 180-181, 186; and Leyte operations, 162, 170-171, 173; and Luzon operations, 186, 192, 195, 196, 197-198; at Noemfoor, 134, 142; and OL YMPIC, 203, 204, 217, 222; and western New Guinea operations, 124, 129, 133, 143,152 Eighth, 29, 217, 228 -Corps I, 195, 217, 218 X, 29, 171 XI, 195,217,218: at Aitape, 147-149 XIV, 29, 195, 196 XXIV, 170 -Divisions Americal, 217 1st Cavalry, 98, 99, 217: at Admiralties, 102-104; at Leyte, 171; at Manila, 197198 6th, 134, 136, 142, 195 24th, 94, 118, 171 25th,217 32d, 41, 59, 62-63, 94: at Aitape, 143; at Buna, 49, 51 33d, 217 37th, 195, 197 4Oth,195 41st, 44, 59, 217: at Biak, 137-138, 141; at Buna, 63; at Hollandia, 118-119 43d, 192, 195, 217 77th, 173, 177 96th,173 -Regiments 5th Cavalry, 104 20th Infantry, 134 112th Cavalry, 90

128th Infantry, 52 158th Regimental Combat Team, 133, 134, 142 163d Infantry, 118-119, 132-133, 143 503d Parachute Infantry, 142 -Battalions 1st Battalion, 162d Infantry, 79 1st Battalion, 163d Regimental Combat Team, 133 2d Battalion, 21st Infantry, 173-174 2d Battalion, 128th Infantry, 150 3d Battalion, 162d Infantry, 138 3d Battalion, 186th Infantry, 138 -Miscellaneous units 2d Signal Service Company, 11 121st Signal Radio Battalion, 20 126th Signal Radio Battalion, 20 837th Signal Service Detachment, 19-20,25 U.S. Intercept Station Number 2,5 U.S. Army Air Forces Far Eastern Air Forces, 29, 212 Fifth Air Force, 29, 80, 81, 119, 228: at Arawe, 90-91; at Biak, 135; defense of Marilinan, 83; raids on Admiralties, 98-99; raids on Hollandia, 111-112; raids on Rabaul, 89-90 Thirteenth Air Force, 29 Twentieth Air Force, 203, 212 313th Bomber Wing, 223 U.S. Army Code and Cipher Section, 8 U.S. Army Forces in Australia, 16, 18 U.S. Army ULTRA assessment of: in December 1942, 57; in August 1944, 151 as basis for Hollandia planning, 108, 110 and Biak, 137 confirms Ho.llandia destruction, 115 confrrms Japanese shipping losses, 100, 155 and convoy interdiction at Hollandia, 106108 detects Eighteenth Army plans, 97, 144 detects exaggerated Japanese battle claims, 168 detects Hollandia air reinforcements, 82-83 detects impending Japanese attack on Aitape, 143-151 detects Japanese buildup in Philippines, 153-155 detects Japanese buildup on New Guinea, 81,83,86,126-128 detects Japanese dispositions on Leyte, 154-155,158-159,166-167,172-173 detects TAKE convoy, 129-131 detects Wewak air reinforcements, 79-81 early reliance on U.S . naval intelligence, 22, 24 effectiveness limited on Luzon, 199

Index and Kyushu, 203-209, 216, 218-220 misses attacks on Hollandia, 119, 127 misses 1st Divisiotl deployment to Leyte, 169, 171 provides estimates of Japanese strength: in Admiralties, 100-103; in November 1942, 49- 51 unevenness of, 194 See also ULTRA ; U.S. Navy ULTRA U.S. Marine Corps: V Marine Amphibious Corps, 217-218; 1st Marine Division, 90; 3d Marine Division, 217; 4th Marine Division, 217; 5th Marine Division, 217 U.S . Navy ULTRA and Bismarck Sea, 68-71 and Buna, 40, 41-43 , 53-54, 57 continuity of, 12-13 contrasted with U.S . Army ULTRA, 13 and Coral Sea, 34-35 cryptologic triumphs (1942) , 33 , 57: detects KON operation, 139-141; de\ects Midway operation, 33; detects New Guinea reinforcements , 42-43,55; detects Operation I, 72- 73; detects Port Moresby operation, 36-37; detects TAKE convoy, 129"":131; detects Toem counterattack, 133; detects Yamamoto flight, 73 exaggerates U.S. Army ULTRA'S limitations, 57- 58 and Leyte, 158 and Leyte Gulf, 161, 162 and prewar codebreaking, 12-13 reasons for early success, 58 as supplier to MacArthur, 22 and Wakde, 127 See also FRUMEL U.S. Navy Amphibious Group 9, 177 Reet Radio Unit, Melbourne (FRUMEL), 15, 16, 24, 89: assists SWPA, 92-93; and Number 81 Convoy, 89 Reet Radio Unit Pacific , Hawaii (FRUPAC),93 Third Reet, 157, 166, 169 VII Amphibious Force, 78 Seventh Reet, 76, 78, 228: at Leyte, 161; as threat at Biak, 135, 138-141 Task Force 38 , 175 U.S . Asiatic Reet, 11 U.S. War Department, xii , 11, 17, 18 , 19, 21, 24, 25 , 48, 71: accuracy of intelligence (November 1942), 49-50; assistant chief of staff, G-2 (Intelligence), 8, 21; and buildup of Japanese air strength on Ho1landia, 109; and buildup of Japanese forces in Philippines, 154-155; and centralized production of ULTRA, 21., 29; and estimates

295

of Japanese strength on Luzon, 181-183, 193; inability to read Japanese army codes, 115; and Leyte campaign, 158, 162, 163, 172; and Military Intelligence Division, 23-24; and Military Intelligence Service, 23, 28; provides substandard order of battle data to MacArthur, 74; and TAKE convoy, 129-131; and ULTRA policies, 28-30 Ushio Heiji, 215, 216 Vertical communications, 33-34 Vogelkop Peninsula, Netherlands East Indies, 94, 134, 136 Wakde Island, Netherlands East Indies, 55, \09, 118, 123, 124, 151, 223: Allied intelligence about, 127-128, 190, 193-194; Japanese air attack on, 137; MacArthur reschedules attack on , 125-126, 129; operations, 133 Washington Peace Conference (1921-22), 8 Wau, North-East New Guinea, 63-64, 66, 67, 77 WE WE code, 37-38 Wewak, North-East New Guinea, 55, 66, 67, 68, 78, 94, 111, 146, 232: airfields at, 56, 61; Allied destruction of, 112 Wewak convoys. See under Convoys Whale (submarine), 100 White, Horton V. : disagrees with Willoughby, 181-182,186-187,192; estimates Japanese strength on Leyte, 166; estimates Japanese strength on Luzon, 181; and Japanese landing at Carigara, 171-172 Whitehead, Ennis C., 61, 69,183 Willoughby, Charles A., 11, 16, 18, 30, 41-42, 229, 235, 271 and Admiralties, 101-102 and Aitape, 144-150: fabricates half-truths about events at , 150-151 and Akin, 20-21 analysis of battle for Leyte Gulf, 161 analysis of kamikaze attacks, 164-166 assessments of Japanese strength: at Arawe , 90; in Bismarck Sea, 68-70; on Biak, 135-136; on Buna, 40-44, 49, 51- 52; in Coral Sea, 36; in eastern New Guinea, 77; at Finschhafen, 87; on Hollandia, 97-98, \07 , 115,116; on Leyte, 157-158, 164, 168, 170; on Luzon, 181-183, 193; in Milne Bay, 44; at Wakde-Sarrni, 126-128, 132-133 attitude toward special security officers, 29 attitude toward War Department, 29 and buildup of Japanese air strength: at Hollandia, 108-109; at Wewak, 80-81 and Central Bureau, 21

296

Index

Willoughby, Charles A. (Continued) and Chamberlin, 17, 23 complains about overreliance on ULTRA, 54 concerned about Allied landing on Mindoro, 188 concerned about buildup of Japanese forces on Kyushu, 204-207, 214-217 concerned about possibility of attack by Japanese fleet, 135-137 deflates battle claims of U. S. pilots after raids on Rabaul, 90 and discrepancies in estimates of Japanese strength on Luzon, 181-183, 186-187 and dissemination of ULTRA, 23, 28, 29 fears compromise of Allied codes, 44, 247 n.30 and Hansa Bay plan, 96-98 and MAGIC, 24-25 and Manila, 195, 197 and navy ULTRA, 24 personality, 16-18 proposes leap to Hollandia, 97-98, 230 reverses previous intelligence assessments, 36,41,59 and Sinkov, 26 superimposes own view on enemy, 44, 59, 145-146,168 and Sutherland, 17

FI

underestimates Japanese strength, 223 uneven performance of, 187 and War Department ULTRA, 29, 49-50 Yagumo Maru (ship), 107 Yamada Eizo, 38, 85-88 Yamagata Force, 49 Yamamoto Isoroku, 235: and Operation I, 72-73; ULTRA detects itinerary of, 73 Yamanaka Akira, 84 Yamashita Tomoyuki, 173, 180, 204, 210: assumes command of Fourteenth Area Army, 159; and battle plans for Leyte, 160, 161, 166, 178; concedes loss of Leyte, 173, 191; and Luzon defenses, 181, 188, 192, 198, 200-201 Yamato (ship), 141 Yardley, Herbert 0., 8-9, 15 Yokosuka Naval Base, Japan, 56 Yokoyama Shizuo, 197 Yokoyama Yosuke, 42 Yorktown (ship), 93 Yoshihara Kane, 67 Yoshino Maru (ship), 156 Yuhara (ship), 13

Z Force, 128

ARY

D 767 .D66 1992 RHC

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