Alvarez, David (editor). Allied and Axis Signals Intelligence in World War II. London: Frank Cass, 1999

ISBN 0-7146-4958-9
229 pages

Foreword; Notes; About the Contributors; Abstracts; Index

   Since RAF Group Captain F. W. Winterbotham's stunning -- although incomplete and not always accurate -- revelations about Enigma and Ultra (the German coding machines and intelligence gained from breaking that system) in The Ultra Secret in 1974, historians have struggled to obtain full access to hitherto inaccessibly classified wartime intelligence files and, given the secrets contained therein, reinterpret the generally accepted story of World War II. The files pried loose from the British and American governments in particular prove that while Ultra might be the most exciting area of research in the field of Signals Intelligence, there is still much to learn about other, less familiar code systems and how they were penetrated and exploited, including "Magic" intelligence gathered from the Japanese.
   In this volume, historian David Alvarez has gathered ten essays from leaders in the field of WWII Sigint research. While each individual piece tends to focus on a very narrow and specific aspect of the broader topic, taken together they offer a general notion of what is currently known -- and, to some extent, what seems to remain hidden -- about Signals Intelligence in the Second World War.

Axis Sigint Collaboration: A Limited Partnership
by David Alvarez
Reviews German collaboration with Hungary, Italy, Finland, Japan, and other friendly nations before and during the war. Briefly assesses Sigint capabilities of each partner (with Finland in particular being highly regarded by the Germans). Many hints about important systems being broken and read. Notes that Turkish traffic was perhaps the most widely penetrated of all major nations. Interestingly, by the end of 1942 certain American diplomatic codes were so widely read and the messages so freely passed around by the Axis that US codebreakers used enemy retransmissions of broken State Department signals as "cribs" into various Axis code systems.

Automating American Cryptanalysis
by Colin Burke
Despite America's reputation for mechanization and automation, the U.S. was unable to take full advantage of electronic and electro-mechanical code-breaking devices until late in the war when the urgency of the task had largely abated. Follows the development of such systems, reviews their technical design and construction, analyzes successes and failures, and places the process within the context of the ebb and flow of the war in general and overall Sigint developments in particular.

Signals Intelligence in Australia during the Pacific War
Frank Cain
Follows pre-war British monitoring of Japanese communications and tracks the Allied Sigint effort based in Australia. After December 1941 this was largely an American-run operation, but included a fully integrated and highly competent team of Aussies. Describes organization and functioning of the various Sigint teams, among them the Australian "Wireless Units". Covers codebreaking, direction finding, traffic analysis, and how the resultant intelligence was actually put to use, including notes about the Australian intercept of Yamamato's itinerary which enabled American fighters to ambush his aircraft.

New Evidence on Breaking the Japanese Army Codes
Edward J. Drea and Joseph E. Richard
One of the best essays in the volume. Details about the Japanese Army code system, down to the color of the covers of the codebooks. Excellent information on how the systems were gradually cracked, including the tardiness with which the Japanese reacted to potential flaws in their system and the fatal use of old codes -- already penetrated by the Allies -- to transmit details of new codes to isolated forces, thus allowing the new codes to be broken. Very interesting material about capturing Japanese codebooks. In at least one case, the Allies intercepted and decrypted a message about codebooks "missing" aboard a sunken barge (which had actually been bombed and destroyed as the result of other Sigint success) in Aitape harbor; this information led to the successful American recovery of the "lost" codebooks and further Sigint penetrations of Japanese codes.

The 'Usual Source': Signals Intelligence and Planning for the Eighth Army 'Crusader' Offensive, 1941
John Ferris
A lengthy and very detailed account of how Sigint affected the planning and outcome of Operation Crusader. Much about Brigadier Eric John Shearer, head of General Staff Intelligence at GHQ Middle East. Many of his contemporaries placed much of the blame for British misfortunes in North Africa squarely in his lap, but Ferris shows that he actually drew mostly the right conclusions -- although not always for the right reasons -- from signals intelligence and other sources. Follows the shaping of Crusader as GSI carefully gleans information about Axis strength and intentions from various sources. Interesting evaluation of the relationship between Churchill's demands for an offensive and Shearer's forecasts about Rommel's situation.

Cautious Collaborators: The Struggle for Anglo-American Cryptanalytic Co-operation, 1940-43
Lee A. Gladwin
One of the stuffier essays. Gladwin delves into the process -- thick with mistrust, uncertainty, and reservations on both sides -- by which the Yanks and Brits finally came to share a remarkably close degree of collaboration in Sigint matters. Makes use of some new materials not available to Bradley Smith when he wrote The Ultra-Magic Deals and the Most Secret Special Relationship which covers similar territory.

Searching for Security: The German Investigations into Enigma's Security
R. A. Ratcliff
This insightful piece sheds much light on German complacency concerning the penetration of their Enigma codes by the Allies. Despite numerous clues that something was seriously amiss, repeated internal investigations found no reason to believe that anyone could possible crack the system. Describes how -- partly due to the fragmented and isolated nature of the German intelligence services and partly due to an unwillingness to believe Enigma was vulnerable -- official inquiries managed to explain away evidence that the Allies were reading German signals.

New Intelligence Releases: A British Side to the Story
Bradley F. Smith
Brief notes about the current state of declassification of wartime intelligence records and information on the mechanics of locating newly released documents in the Public Record Office in Kew. Least substantial of the lot.

Signals Intelligence and Vichy France, 1940-44: Intelligence in Defeat
Martin Thomas
Begins with the state of French intelligence services at the outbreak of war and follows them, and their personnel, through their relationships with the Germans, the Allies, the Vichy government, and the Free French. A surprisingly significant proportion of key intelligence agencies survived the 1940 collapse and armistice intact, partly due to careful concealment by protective officers and politicians. Although some Sigint resources were deployed against the Allies, notably for the protection of French colonies, for the most part Germany was still considered the ultimate opponent against whom the French intelligence teams devoted most of their efforts. Reveals how French agencies routinely relayed intercepted German military traffic from Vichy to Allied contacts in England.

Chinese Codebreakers, 1927-45
Maochun Yu
In this essay on a little-known facet of the Chinese war effort, Yu raises the curtain on Chiang Kai-shek's Signit apparatus. Split by political and bureaucratic rivalries, multiple agencies attempted independently to crack Japanese military codes, mostly without success until China hired the famous (or infamous) American expert Herbert Yardley to lead its efforts. (Elsewhere in this volume, by coincidence, it is explained how American agencies refused to provide much Sigint material or assistance to China so long as Yardley remained in their employ.) Yu claims for the Chinese substantial successes by 1942 to the extent that they warned -- but were ignored -- about specific Japanese air raids in Burma and later were tricked into sending a team of cryptanalysts to India in order that the British could surreptitiously acquire Chinese techniques for breaking Japanese codes.

   Despite some unevenness -- several of these pieces are excellent while a couple are rather weak -- in sum this is a terrific collection of Sigint essays. However, that praise must be slightly qualified. That is, to a certain extent, many of these essays seem to be aimed at those already familiar with the field: in some cases basic background and definitions are in short supply and in other cases tantalizing facts are tossed into the text without further explanation, as though they are common knowledge. In that sense, while it's still possible to highly recommend this volume, it definitely serves for interested readers more as a beginning point for further exploration than as a detailed, comprehensive survey of the vast, complicated, and shadowy history of Signals Intelligence in World War II.
   Available from online booksellers, local bookshops, or directly from Frank Cass. Distributed in the US by International Specialized Book Services.
   Thanks to Cass and ISBS for providing this review copy.