The Emperor's Codes

by Michael Smith

In this gripping, previously untold story from World War II, Michael Smith examines how code breakers cracked JapanOCOs secret codes and won the war in the Pacific. He also takes the reader step by step through the process, explaining exactly how the code breakers went about their daunting taskOComade even more difficult by the vast linguistic differences between Japanese and English.
"The EmperorOCOs Codes" moves across the world from Bletchley Park to Pearl Harbor, from Singapore to Colombo, and from Mombasa to Melbourne. It tells the stories of John Tiltman, the British soldier turned code breaker who made many of the early breaks in Japanese diplomatic and military codes; Commander Joe Rochedort, the leading expert on Japanese in U.S. naval intelligence; Eric Nave, the Australian sailor who pioneered breakthroughs in deciphering Japanese naval codes; and Oshima Hiroshi, the hard-drinking Japanese ambassador to Berlin whose candid, often verbose reports to Tokyo of his conversations with Hitler and other high-ranking Nazis were a major source of intelligence in the war against Germany. Without the dedication demonstrated by these relatively unsung heroes, the outcome of World War II might have been very different."

Genres: History, Nonfiction, World War II, War, Military History, Espionage, Japan

480 pages, Kindle Edition

First published January 1, 2000

About the author

There is more than one Michael Smith in the database.

Michael Smith is a British author and screenwriter who specializes in spies and espionage.

Source: Wikipedia.

Reviews

[Dj · Rating 3 out of 5]

This book is a little outside my comfort zone. Not because of the subject matter, which I found intriguing, but due to the fact that the actual workings of decryption involve a lot of math that is outside my ability to follow along. The author goes over a 'simple' example of working a code and by the third line of working the problem I am completely lost and just nodding along and thinking to myself I will take your word for it.

Fortunately enough for yours truly that didn't happen very often. The thing most intriguing about the book is it focuses on British efforts to break Japanese codes. The use efforts get mentioned quite a lot either wholesale or in passing in almost every book that I read recently about the War in the Pacific. There is a very good reason for this. US Intelligence sources were key in a number of victories in the Pacific, Midway is just one of the most prominent.

This book forgoes the tale of the US and looks at the British and their Commonwealth Allies in regards to Code Breaking. While not as impressive as the results of the Midway outcome, there are a number of instances where British efforts assisted both MacArthur and Slim. Sometimes they were reading Japanese Codes and delivering the information at nearly same time to those South Pacific Commanders. The codes in question were Army Airforce codes that gave an impressive amount of information.

The book also looks at the training and lifestyle of the people involved. This is a look at lives of people that normally don't get to play a leading role in the histories and sometimes it is very humorous. Not so funny is the clashes between the US and the British at the higher Administration levels over the sharing of information. It seems that those in charge of the US side didn't play well with others. The Author points to the treatment of Joe Rochefort as an example of just how petty they could be.

All in all a very informative book.

[Michael Burnam-Fink · Rating 4 out of 5]

By this point, the greatest secret of the Second World War is common knowledge. The allies had broken key Axis codes, and generals and admirals were guided by signals intelligence. Reading the enemy's mail provided insight into everything from strategic thinking to the readiness levels of specific fighter squadrons. The Emperor's Code is a biography, mostly of the British efforts against Japanese naval codes. It's livened by details about being a codebreaker then, boffins and retired diplomats and WRENS and Indian auxiliaries and other fringe types crammed together in sweltering radio huts, puzzling over grids of numbers in the hopes of finding some intelligence.

Imperial Japan took a characteristically arrogant approach to cryptography, assuming that Japanese was so complex no Westerner could read it. They were almost right, but they were also careless, using crypto systems that were barely random, re-transmitting messages in secure and broken systems simultaneously, and using stereotyped formats that provided easy 'cribs' for deciphering. The Allied effort was riven by technical and political difficulties. The main British codebreaking center in the East moved from Singapore to Sri Lanka to Mombasa in the course of the great retreat in 1942, with obvious implications for efficiency. Bletchley Park devoted most of its resource to crackign the Nazi Enigma cipher and winning the Battle of the Atlantic, and then swept in and demanded a leadership role. And if there's a villain in this book, it's the American Commander Rudi Fabian's FRUMEL unit, canny bureaucratic warriors who in Smith's telling preferred turf-building over breaking codes.

This book is long, and buries some key historical moments in the mass of details. Japanese codes were constantly changing, and could only be broken after sufficient depth of messages had accumulated. The diplomatic 'Purple' cipher had been broken by the Americans, and that combined with other breaks allowed Allied intelligence to conclude that something was up prior to Pearl Harbor, but not the specifics of the initial attacks. Conversely, the Battle of Midway came towards the end of code's period, and in fact several weeks past a scheduled turn-over in codes. This meant that the entire operational order for Midway was broken. At the end of the war, in the Summer of 1945, codebreakers caught a diplomatic message to the Soviet Union attempting to negotiate peace on terms that included the continued safety of the Emperor and the political integrity of the four home islands. These conditions were compatible with the actual American terms, no matter the harsh rhetoric of 'Unconditional Surrender', but for whatever reason (Soviet duplicity, Allied paranoia about signals intelligence), this message was not brought up at the Potsdam conference, and the atom bomb was dropped.

The Emperor's Codes is best as an oral history of codebreakers, and has some structural weaknesses, but it's still a fascinating and worthwhile military history.

[Murilo Silva · Rating 2 out of 5]

Spends too much time explaining how the lives of the codebreakers were at their respective places of operation. Doesn’t get into the details of how the encryption/decryption worked (which is necessary to understanding it) neither is superficial enough to be readable. The central idea is explaining the process of how the British and Australians were key in the breaking of Japanese codes enciphered by the Purple Machine (or Type B) (diplomatic codes more importantly, because the military used a different and nearly unbreakable [one-time pad] encryption system), but then the task was transferred to the Americans, because the British got too busy with German Enigma.

[David · Rating 4 out of 5]

The Emperor's codes goes into great detail about all of the code breaking efforts on the part of the British and Americans during WWII. It is focused primarily on the Pacific Theater and the many different sets of codes used for diplomats, navy, air to ship, air to air, and others. It does also touch on activities to break the Nazi Enigma codes. Mostly a very fascinating read but what I found frustrating was keeping up with the myriad names of the participants in England, America, Philippines, India, Australia, and many additional locations that would move depending on the progress of the war. There were many major breakthroughs that inevitably saved lives and shortened the war by as much as two years. There is even a chapter that demonstrates how codes were broken using actual data as it goes step by step through the process.

[David R. · Rating 3 out of 5]

A thoroughly interesting account of the work and setbacks behind the effort to crack the Japanese military codes in the WW2 Pacific Theater, from the perspective of the British armed forces. It suffers from some organizational issues as well as an unnecessary degree of Anti Americanism.

[Ian Chapman · Rating 4 out of 5]

Interesting account of Allied efforts against Japanese codes, with some rightful highlighting of the Australian contribution.

[Frumenty · Rating 4 out of 5]

My mother, maiden name Gloria Patricia Stevens, served in the Women’s Royal Naval Service (WRNS, a.k.a. Wrens) in WW2. She was at Bletchley Park, I have been told, most probably in Hugh Foss’ Hut 7, where codebreakers were at work on Japanese codes. The Japanese surrender occurred just weeks before her 20th birthday. I remember her telling me that she had served in “naval intelligence”. She didn’t elaborate, but evidently regarded that word “intelligence” as a compliment to herself. She also mentioned having been billeted at Woburn Abbey. She recalled that her boss was an eccentric Scot who put on a show that included a “sword dance”. Hugh Foss was an enthusiastic Scottish dancer. Since I only learned about a place called Bletchley Park after her death, I missed the opportunity for an informed discussion of her experiences. Her presence at Bletchley was confirmed by the people who now run Bletchley as a historical and cultural institution, on the basis of a shift roster and testimony of a person or persons who recalled her by name. I was naturally eager to read this book.

This is not the first book I’ve read about Bletchley Park, nor even the first of Smith’s books about it. It’s the first I’ve read that doesn’t focus on the breaking of the German “Enigma” code. More than other books I’ve read, this one demonstrates the extent to which the effort to break Axis codes was an international effort. Australia’s contribution is acknowledged, especially the important work of Eric Nave. The book’s title is a little disingenuous inasmuch as Bletchley, though important, isn’t so central to the effort to break Japan’s codes as seems to be implied. US operations were bigger, but Bletchley sells books so the publishers may have insisted. Smith is very critical of the US Navy for having hindered cooperation, for much of the war, with Britain and even with the US Army in the matter of signals intelligence.

By late in the war Allied knowledge of Japanese plans and activities was so complete that, it seemed to me, only massive Allied incompetence could have saved the Japanese from defeat after defeat after defeat. I almost felt sorry for them. Reading this book I came to appreciate, more than ever before, the impact of “traffic analysis” as an intelligence tool. Even had the Japanese codes been quite impenetrable, sophisticated Allied traffic analysis operations would still have provided intelligence of immense importance to Allied strategists.

I was tickled to read (p.327) that the BBC was involved in what seems, in light of extreme post-war efforts to keep the Bletchley secret, a rather extraordinary lapse of security. Shortly after the German surrender Bletchley Park was introduced to the entire British nation by a Sunday morning musical broadcast which showcased the remarkable concentration of musical talent there. Did nobody wonder why so many gifted people, in this case musicians, came to be gathered in this place of so little renown, for music or for anything else?

This is a thorough and very competent treatment of a complex topic. If you’re sufficiently interested you won’t be disappointed.

[Mal Warwick · Rating 3 out of 5]

Americans have long believed it was homegrown efforts that succeeded in deciphering the World War II Japanese military and diplomatic codes — and that belief is significant, because otherwise the Battle of Midway and other pivotal events in the Pacific War might have gone differently. But here’s Michael Smith, who asserts in The Emperor’s Codes that it was actually British code-breakers who were largely responsible.

Smith writes that Britain’s Official Secrets Act prevented the release of this information for decades after World War II, while the Americans rushed to claim success even before the war had ended. However, given the story as he tells it, the truth seems to lie not in either camp but as expressed in the book’s subtitle: The Thrilling Story of the Allied Code Breakers Who Turned the Tide of World War II. Though shakily at times, and in some ways not at all, Britain and the US closely collaborated on intelligence matters. Both countries made significant contributions to breaking the Japanese codes. Neither could have accomplished it unassisted.

A plethora of World War II Japanese codes

In the popular histories of the Pacific War, most of the attention has gone to the so-called Purple cipher and the Japanese naval code designated JN25, which apparently were the most significant of the World War II Japanese encryption systems. American authors tend to credit the US with having cracked both of them, while Smith asserts that collaboration with the British at Bletchley Park and in Asia was crucial. What Smith also makes clearer than many other authors, however, is that the Japanese — like all the major combatants — employed many different codes and ciphers in the course of the war. And there were frequent changes that challenged code-breakers even within each of them. Deciphering all these systems required the work of hundreds of people around the world and often around the clock. And at no point did either the Americans or the British arrive at a permanent solution to Japanese encryption. The same was true, by the way, of the famous German Enigma codes, which went through a long series of changes and enhancements.
An account that falls flat

Reading The Emperor’s Codes is sometimes a challenge. Unlike Ben Macintyre and other better-known authors who have written about espionage in World War II, Smith dwells on process and procedures, not people. Even the individuals who served the longest and at the highest levels of the British and American code-breaking operations drift in and out of the story, never coming clearly into focus. The result is a tale that falls flat.
About the author

There are, of course, many authors named Michael Smith, and that presented a challenge for me to learn anything about his background. But apparently this Michael Smith is a former British military and intelligence officer and journalist who has written more than a dozen books about espionage. He was born in 1946 and lives in London.

[Jrobertus · Rating 3 out of 5]

This book is by a Brit and focuses on their efforts to crack the Japanese WWII codes. He is trying to redress the notion that the code breaking was largely an American effort. He spends a lot of time emphasizing how amateurish the initial American efforts were, and how the U.S. navy cryptanalysts were uncooperative with the Brits and Australians. This may all be true but the subsequent British leaks to the Soviets may support a sense that this was not entirely unwarranted. He rather grudgingly admits to the weight of the American effort in code breaking and to the actual combat that defeated Japan. Anyway, the book was pretty interesting, describing the lives of young scholars recruited to work in unpleasant places to crack these vital codes; very engaging human stories indeed. The book also describes the difficulties of deciphering these complex codes and ciphers and even has a simplified example of what needed to be done; it seems way over my head. The history related to the programs was also fascinating. The Japanese ambassador to Berlin was often taken into Hitler’s confidence since he was trying to convince them to invade the USSR. The ambassador’s messages to Tokyo were deciphered and gave the West a lot of information about German plans. They revealed the intention to invade Russia, which was revealed to Stalin, but he refused to believe it! Finally, most ot the British and Aussie cryptanalysis dealt with the War in New Guinea and Burma and so the book provided a rather novel view of a part to the Pacific campaign unfamiliar to Americans.

[Rich · Rating 4 out of 5]

An illuminating and detailed account of allied codebreaking in WW2 against Japanese ciphers and codes.

This was well researched and detailed account of allied codebreaking throughout the 1930s and second world war with emphasis on the Japanese codes. It was well written with many personal stories interleaved to add interest and colour to what could otherwise be quite a dry subject.

I came away with a much better appreciation of the immense and sustained human effort and brilliance needed to 'break' the enemies codes, the surprising number of these codes, how the information was distributed and the overall impact on the war in the east. I am amazed that our level of success remained a secret throughout the war. But I was also dismayed by the politics at a top level between the US and UK and how that hindered efforts and undoubtedly cost lives.

There were a few very detailed accounts of how certain codes were broken but it seems there were not many mechanical or electronic machines involved in the breaking of these codes, only the IBM/Hollerith tabulating machines. Not much technical detail is provided about these, and nothing more than a mention of the bombes and other machines used at Bletchley Park to break the codes used in other theatres of the war.

A very good account for those interested in the subject.

[Brian Meadows · Rating 1 out of 5]

It took me forever to read this book. I even laid it aside in disgust for many months before picking it back up to finish it. The biggest problem I had was the British arrogance being evident throughout. According to the book, the British code breakers were the world leaders and everyone else, especially Americans, were bumblers. They were entitled for everyone else to run their codebreaking efforts through them at Bletchley Park. I take exception as my wife's great uncle and aunt, William and Elizebeth Friedman, were some of the original groundbreakers in cryptanalysis. They laid the groundwork for all that was done and honored by being laid to rest at Arlington. William only got a passing mention in the book for breaking the Japanese code Purple that made the success in World War II possible. Books written about them allude to the friction going on between the American and British codebreakers, but I had no idea how deep the animosity ran. Granted that the American high command was not error free during the war but neither was the British.

The book was also detailed and loaded with quotes to support the author's bias. It was very difficult to follow the discussion about the techniques of breaking codes. It is admittedly complex (or anyone could do it) but I found the author's discussion quite perplexing. I believe this has a lot to do with the British way of explaining technical information being different from American vernacular. In sum, I do not recommend this book.

[Kate · Rating 4 out of 5]

At times, this book gets rather technical. But it is fascinating to learn about the people who often did not master Japanese, were trained and then started translating. The book has parts where all this is explained in great detail - but this was just too technical for me.

Very odd, that so much attention was paid to Bletchley's efforts on Enigma; with hardly any attention paid to its involvement in breaking Japanese codes. Extremely sad: the pettiness, small-mindedness and worse of Americans who broke brilliant careers, refused to fully cooperate, share all they discovered. This will undoubtedly be glossed over in any Hollywood film - if ever there is made one.

Also the fact re the negotiations with Japan and the unnecessary dropping of 2 atomic bombs. It is rather sickening to learn this. As one of many who had family members who suffered at the hands of the Japanese, I was also left wondering if the attitudes of a few ensured the war in the Pacific lasted longer than necessary.

[Bill Conrad · Rating 3 out of 5]

This is another book I came across by accident, and the title sounded intriguing. Richard takes a deep dive into the roll that roll intelligence gathering played WWII, Japan. A big part of intelligence is getting relevant information to the right place at the right time. Richard did a great job of explaining this time frame and the people involved. This decoided information then allowed the decision makers to make better choices, and Richard provided the battle results. Richard also described many of the code-breaking methods and the logic behind them.
I liked the subject matter of this book and the way the book was laid out. I would have preferred more detail about the code machines and the exact techniques. I felt that the reader needed to have beforehand codebreaking knowledge to understand this book’s message. It does have one annoying aspect; the dialog. I found it difficult to separate the narrative from the dialog. Still, I did get a lot out of this book. and I found it entertaining.

[Ollivier · Rating 4 out of 5]

This book, especially read after "Battle of Wits" (and multiple reading of Kahn's The Codebreakers) shed a entire new light on the codebreaking of the famous Japanese code called JN25 (a great part of the victory at Midway & killing of Yamamoto came from the breaking of that code).

Nowhere before did I see mention of the immense work done at Bletchley Park, including the fact that Tiltman broke JN25 way before the Americans did and they the multiple interception stations by the Brits provided a great part of the additive keys & code words during the War.

Part of what is in the book was unclassified by the Brits years after the Americans did it for their part but still, it is surprising that it was not known before.

Very interesting read.

[Neil Hunt · Rating 3 out of 5]

Interesting, but long

Fascinating story of breaking a wide range of codes used by the Japanese. There is a small section walking through the process of breaking the codes, describing aligning the groups by "additive", guessing common words to try out different additive values, validating with various other sources, and gradually building up the underlying code books.

The collaboration, or lack of collaboration, between Britain and the US Is a major theme.

The book uses the device of lengthy quotes or excerpts from memoirs of from hundreds of individuals involved, which paint a clear picture of life during the war at Bletchley, Washington, Melbourne, and more interesting, at many forward and field posts in India, Ceylon, and throughout the Pacific region.

[Daniel Q · Rating 4 out of 5]

This is a good account of the efforts by England (and allies) to gather information from Japan's encoded communications in World War II. It is not very deep in technical information and does not cover the machine-based ciphers (that were broke by US), but gives a good idea of the real work involved. Forget the lone genius in the Hollywood movies that magically makes all communication readable in real time. This is a story involving thousands of people working really hard to obtain partial decodes and having to (sort of) start again each time a change was made by the Japanese. Lots of quotes from people that participated in the effort help to give a "human angle" to the narrative.

[Bill Taylor · Rating 3 out of 5]

The story of allied code-breaking during WW II certainly should be narrated in depth. For that reason I rated this book as I did; otherwise I consider the author’s attempt as lacking focus, organization, and an engaging style.
The book is “peppered” with observations of the many participants in this enterprise and focuses chiefly on British-Australian contributions against the Japanese. Certainly working through this book will provide an understanding of the breath and importance of cryptography to the Allied success in WW II.

[Mike Thiac · Rating 4 out of 5]

A bit tedious at times, but an excellent look at how Great Britain, alone with the United States, worked to break the communications codes of the Japanese Empire. I've read several books on the work England with against the Germans and the Enigma system, this is the first time I've looked at the Pacific War, and the efforts that went into there. Arguable, the efforts of the intelligence branches saved thousands of lives and shortened the war. Highly recommend for anyone interested in World War II in general, and intelligence operations in particular.

[Andrew Scholes · Rating 4 out of 5]

t was well written and not too technical. I had read another book that really got into excruciating detail of codes and how they were translated and pages upon pages of code. I found it interesting how close to the vest each of the allied code breaker services held their information. For much of the war they did not and would nto share information of codes that were broken or clues they found to break the codes.

[NRVOUTDOORSMAN · Rating 4 out of 5]

Interesting read

Very interesting look at the importance of code breaking and its importance in the Pacific theater, a nice complement to the better known story of Ultra in the European theater. At times its hard to follow unless you know something about cryptanalysis because the author occasionally dives into discussions that are moderately technical, but all in all a worthwhile read for anyone interested in WW 2 history.

[Charles W. Jennings · Rating 3 out of 5]

Interesting read, however, at times it laborious to get through. It surprised me at the level of animosity between "Allied" forces, I had always thought that allies had the best interest of the partnered countries not competing with one another. The backbiting and distrust was surprising. I thought some of the chapters could have consolidated for the informed reader.

[Ann Marie · Rating 5 out of 5]

Wow. I had no idea.

I am a history buff and especially around D day focus on WWII. I had no idea of any of this except for the Battle of Midway. The way the code breakers worked was fascinating and seemingly impossible. The differences they made were huge. So disappointed in the petty actions of some of the leaders.

[Kevin Reeder · Rating 3 out of 5]

Packed with knowledge about WWII code breakers

Interesting historical pice about how we won the war by breaking the coded messages. Fascinating information I never knew. Good read.

[Tom Mahan · Rating 3 out of 5]

An interesting look at the people behind breaking the Japanese codes used during WWII. It is also a good look at the interservice rivalries between the British and American sig/int units all over the world. A wealth of information, but also a bit dry.

[John G · Rating 4 out of 5]

Much to be learned

A very readable book on the important part that codebreaking played in the Pacific theater in WW2. It is good to learn how all this came about.

[Kristi · Rating 3 out of 5]

Interesting read, but it definitely bogs down in places. There are too many names, places, and code variants to keep track of them all.

[Robert M. Galbraith · Rating 5 out of 5]

This is a fascinating account for anyone interested in WWII history. I had no idea of the extent of the effort by British and American codebreakers of the variety of tools used to track the enemy.

[Benny · Rating 2 out of 5]

Way too much detail.

[Daniel · Rating 1 out of 5]

Such an interesting topic so boringly told. Too much blather about who was where when. Finally 2/3 of the way through he started to try to explain code-breaking, but by then you just wanted it to be over. Some interesting anecdotes about the successes and struggles but not nearly enough.

[Mark Maddrey · Rating 3 out of 5]

I found this to be a decently informative overview of the Allied code breaking effort on the Japanese codes, but I could not help feeling like something was missing. The book never came alive for me in the way that creative non-fiction books by writers such as Erik Larson, Steven Johnson, or Simon Winchester do. I felt like I was reading a school paper that went through everything that happened in order. Everything was there but it was inert. I also felt like the author's stated opinion that the Americans get too much credit for breaking these codes and the British too little informed his writing a little too much. There were points where it seemed like he had just told us the Americans had done all this great work and he would then say that the British really deserve credit for it. Odd. It was very interesting to read about these efforts, clearly much more ink has been spilled over the breaking of the ENIGMA machine code, and I think it is important to remember this story also. I'm just not sure this is the best book to do so.