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Decoding the Devil: Black Women Codebreakers and the Secret War Against Stalin's Bomb
Decoding the Deviltells the shocking true story of two segregated codebreaking units in the Army's intelligence agencies during World War II and the Cold War.
The result of a racial hiring quota, the Commercial Code unit freed the US from relying on British intelligence on the Axis powers’ trade relations and broke critical Japanese codes.
Led by William Coffee, the unit employed professors, college graduates, and other professionals who decrypted and translated messages from Spanish, German, Italian, French, and Portuguese.
After World War II, the Russian Plaintext Unit countered the growing threat of Soviet nuclear war. A top-secret operation, the all-Black unit worked under armed guard and was the Allies’ main source of intelligence on the Soviet atomic program from 1947 until the early 1950s.
Decoding the Devil highlights the Black cryptologists’ critical contribution to national security in the civil rights era and promises to captivate readers with its fresh perspective on this pivotal moment in American history.
The result of a racial hiring quota, the Commercial Code unit freed the US from relying on British intelligence on the Axis powers’ trade relations and broke critical Japanese codes.
Led by William Coffee, the unit employed professors, college graduates, and other professionals who decrypted and translated messages from Spanish, German, Italian, French, and Portuguese.
After World War II, the Russian Plaintext Unit countered the growing threat of Soviet nuclear war. A top-secret operation, the all-Black unit worked under armed guard and was the Allies’ main source of intelligence on the Soviet atomic program from 1947 until the early 1950s.
Decoding the Devil highlights the Black cryptologists’ critical contribution to national security in the civil rights era and promises to captivate readers with its fresh perspective on this pivotal moment in American history.
368 pages, Hardcover
First published June 2, 2026
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Displaying 1 - 13 of 13 reviews
July 8, 2026
An Important Walk In The Shoes Of “The Other”
I grew up in a white town, went to lily white schools and beamed that I was NOT racist. But here’s the thing. Until I went to university I’d never personally met a black person. My parents hated no one, but had deep, intrinsic racial beliefs that they perpetuated but never recognized.
Now, years later as a senior citizen I have quite a few close black friends who, I believe, understand that I have a good heart, so have seen their way clear to educate me about the daily reality of being black in America. One of their suggestions is to read more.
Books like this one make it abundantly clear that people like me may have nobility of heart, but our understanding of racism is lacking.
This book is very academic, well researched and hard to ignore thanks to the real people we get to known in the book.
The setting is the Cold War and spy craft, but the real subject is racism and sexism, and white willingness to remain in the dark about it.
This is an important read.
I grew up in a white town, went to lily white schools and beamed that I was NOT racist. But here’s the thing. Until I went to university I’d never personally met a black person. My parents hated no one, but had deep, intrinsic racial beliefs that they perpetuated but never recognized.
Now, years later as a senior citizen I have quite a few close black friends who, I believe, understand that I have a good heart, so have seen their way clear to educate me about the daily reality of being black in America. One of their suggestions is to read more.
Books like this one make it abundantly clear that people like me may have nobility of heart, but our understanding of racism is lacking.
This book is very academic, well researched and hard to ignore thanks to the real people we get to known in the book.
The setting is the Cold War and spy craft, but the real subject is racism and sexism, and white willingness to remain in the dark about it.
This is an important read.
July 12, 2026
Wanted to like more but several boring parts
June 14, 2026
In DECODING THE DEVIL, noted author Sarah Valentine presents a revelatory account of little-known but significant American history: the employment of Black American women to monitor sensitive, secret data regarding the regime of the USSR and its efforts to develop nuclear weapons.
In the post-World War II era, computerization was a new phenomenon. Those who utilized its benefits would need to be highly educated, yet willing to work as undercover agents for low pay in harsh conditions and under the pressure of racial prejudice, which was especially prevalent in Washington, DC. Blacks who lived “under constant threat” were likely candidates to toil for what were known as Code Units.
Valentine’s impressively detailed work focuses on four of these indomitable women: Naomi McElwaine, a Purdue graduate; Ethel Just, whose expertise was the German language; Iris Carr, a Texas schoolteacher; and Minnie Kenny, who developed special knowledge of both Chinese intelligence and cybersecurity.
Through their eyes, Valentine depicts grueling workdays spent in specially segregated buildings and basements under armed guard, the complexities of the regulations to be followed, and the punishments that might ensue for disobedience. She offers scrupulous research concerning the era, with reminders of the Ku Klux Klan, the ideology of the Cold War, America’s exploration of the efficacy of nuclear protection and aggression, the effects of such rebellious personalities as African-American actor and activist Paul Robeson, and the prevalence of beliefs that not only were Black people inferior, but that their very blood was a “contaminant.” Perhaps most telling was the official designation of the women’s workplace as the Traffic Processing Division, which was privately referred to by its managers as The Plantation.
Valentine professes a strong personal attachment to the subject matter that she so diligently shares. Beginning with a talent for poetry, she became drawn to Russian literature. After achieving a PhD, she started to explore her experiences as a mixed-race person, composing the award-winning essay (and eventual memoir) “When I Was White.” DECODING THE DEVIL features a plethora of factual material concerning governmental policies, computer complexities, terminologies such as Book Cipher and Machine Cryptanalysis, and brief biographical portraits of such historical figures as Eleanor Roosevelt, Joseph Stalin and Kim Philby.
Readers new to Valentine’s chosen, vividly arrayed portraits of Black women willing to toil on behalf of a nation that generally scorned them, as well as those with inherent interest in the verities of their courageous work, will wish to further explore her literary offerings.
Reviewed by Barbara Bamberger Scott
In the post-World War II era, computerization was a new phenomenon. Those who utilized its benefits would need to be highly educated, yet willing to work as undercover agents for low pay in harsh conditions and under the pressure of racial prejudice, which was especially prevalent in Washington, DC. Blacks who lived “under constant threat” were likely candidates to toil for what were known as Code Units.
Valentine’s impressively detailed work focuses on four of these indomitable women: Naomi McElwaine, a Purdue graduate; Ethel Just, whose expertise was the German language; Iris Carr, a Texas schoolteacher; and Minnie Kenny, who developed special knowledge of both Chinese intelligence and cybersecurity.
Through their eyes, Valentine depicts grueling workdays spent in specially segregated buildings and basements under armed guard, the complexities of the regulations to be followed, and the punishments that might ensue for disobedience. She offers scrupulous research concerning the era, with reminders of the Ku Klux Klan, the ideology of the Cold War, America’s exploration of the efficacy of nuclear protection and aggression, the effects of such rebellious personalities as African-American actor and activist Paul Robeson, and the prevalence of beliefs that not only were Black people inferior, but that their very blood was a “contaminant.” Perhaps most telling was the official designation of the women’s workplace as the Traffic Processing Division, which was privately referred to by its managers as The Plantation.
Valentine professes a strong personal attachment to the subject matter that she so diligently shares. Beginning with a talent for poetry, she became drawn to Russian literature. After achieving a PhD, she started to explore her experiences as a mixed-race person, composing the award-winning essay (and eventual memoir) “When I Was White.” DECODING THE DEVIL features a plethora of factual material concerning governmental policies, computer complexities, terminologies such as Book Cipher and Machine Cryptanalysis, and brief biographical portraits of such historical figures as Eleanor Roosevelt, Joseph Stalin and Kim Philby.
Readers new to Valentine’s chosen, vividly arrayed portraits of Black women willing to toil on behalf of a nation that generally scorned them, as well as those with inherent interest in the verities of their courageous work, will wish to further explore her literary offerings.
Reviewed by Barbara Bamberger Scott
Review of advance copy received from Publisher
Thank you Harper Books for sending me a free advance copy!
3.75 stars
Codebreaking is something I’ve had an interest in and over the years I’ve read a handful of nonfiction and historical fiction books on the subject. DECODING THE DEVIL is a rather unique nonfiction read as it looks at the contributions of Black women in this area of expertise during World War 2 as well as the Cold War era. They were overworked, underpaid, subjected to menial tasks far below their capabilities, and segregated from white units. Finally, decades later they are getting some sort of recognition for their hard work.
Given the secretive nature of the job and classified information, it’s doubtful we will ever get the full story of all the Black women codebreakers. The author did a good job piecing together as much as she could and paints the picture of how it was a thankless job for these women. They got zero support. It was a tough, hostile, and racist environment and given it was a government job, that’s even more shameful.
In addition to highlighting some of the codebreakers, the author goes into the different laws and policies that screwed over Black people during this time. Hundreds of Black families were displaced after their homes were torn down in order to build the Pentagon. Wage discrimination was a huge issue. While this book is informative on the codebreaking side it’s also a worthwhile read for learning more about the uphill battles Black people faced during this era.
3.75 stars
Codebreaking is something I’ve had an interest in and over the years I’ve read a handful of nonfiction and historical fiction books on the subject. DECODING THE DEVIL is a rather unique nonfiction read as it looks at the contributions of Black women in this area of expertise during World War 2 as well as the Cold War era. They were overworked, underpaid, subjected to menial tasks far below their capabilities, and segregated from white units. Finally, decades later they are getting some sort of recognition for their hard work.
Given the secretive nature of the job and classified information, it’s doubtful we will ever get the full story of all the Black women codebreakers. The author did a good job piecing together as much as she could and paints the picture of how it was a thankless job for these women. They got zero support. It was a tough, hostile, and racist environment and given it was a government job, that’s even more shameful.
In addition to highlighting some of the codebreakers, the author goes into the different laws and policies that screwed over Black people during this time. Hundreds of Black families were displaced after their homes were torn down in order to build the Pentagon. Wage discrimination was a huge issue. While this book is informative on the codebreaking side it’s also a worthwhile read for learning more about the uphill battles Black people faced during this era.
July 6, 2026
Thank you to Harper for the free book. These opinions are my own.
I think it is so important to learn about the aspects of history that are not as frequently shared. I am glad to have read this story of Black women codebreakers. It's set in the wake of World War 2 during the Cold War.
This nonfiction is very well researched and grounded in fact. Yet it reads like fiction at times. The prose is incredibly engaging. We follow the stories of multiple women throughout their careers. In writing this, the author lays out both the individual and the broader context.
I can't say I am fully surprised to learn about the segregation and poor treatment, continuing long past when both were illegal in the federal workforce. Moreover, there is the intersectionality of dual discrimination that Black women face. And I am not all that surprised that such unethical choices also were poor management decisions that made it harder to gain intelligence and protect national security.
I'm grateful to Sarah Valentine for her work in uncovering and sharing these histories.
I think it is so important to learn about the aspects of history that are not as frequently shared. I am glad to have read this story of Black women codebreakers. It's set in the wake of World War 2 during the Cold War.
This nonfiction is very well researched and grounded in fact. Yet it reads like fiction at times. The prose is incredibly engaging. We follow the stories of multiple women throughout their careers. In writing this, the author lays out both the individual and the broader context.
I can't say I am fully surprised to learn about the segregation and poor treatment, continuing long past when both were illegal in the federal workforce. Moreover, there is the intersectionality of dual discrimination that Black women face. And I am not all that surprised that such unethical choices also were poor management decisions that made it harder to gain intelligence and protect national security.
I'm grateful to Sarah Valentine for her work in uncovering and sharing these histories.
June 10, 2026
This book is MUST READ. One of the book's greatest strengths is its focus on individuals who have received little recognition despite their significant contributions to national security. Valentine highlights the experiences of highly educated Black women who worked under difficult conditions, facing racial segregation, geometry dash spam, wage disparities, and limited opportunities even while performing critical intelligence work. The book succeeds in combining espionage history with social history. Rather than presenting codebreaking as a purely technical subject, Valentine explores how race, gender, and politics intersected within the intelligence community.
July 5, 2026
This was a fantastic read, thanks to the publisher for sending me a copy via a giveaway. After reading Hidden Figures some years ago, I became very interested in learning more about unsung women of color who made a difference in advancing science and technology. This book was a perfect addition to my shelf. I am so glad I got to learn about the critical role played by Black women codebreakers for the security of the United States at a time when segregation and racism were prevalent in ways we cannot imagine today. Will definitely be recommending this for book clubs, especially for Women's History Month!
June 23, 2026
This book was surprisingly novelistic. Even though it is grounded in historical events the women's lives carry the narrative, making it an extremely compelling read. They face unimaginable hardships but are inspiring in what they were able to accomplish, inside and outside of the NSA.
On a genre note, I didn't know much about codebreaking before reading this book, and I was glad that it wasn't too technical. The book includes a detailed glossary with people, places, events, and specialized terms at the end, which I found very helpful. Great summer read, highly recommend.
On a genre note, I didn't know much about codebreaking before reading this book, and I was glad that it wasn't too technical. The book includes a detailed glossary with people, places, events, and specialized terms at the end, which I found very helpful. Great summer read, highly recommend.
July 1, 2026
In an early chapter discussing the buildup following Pearl Harbour, the author mentions rhat RCA iis concentrating on rhe manufacturer of tubes and transistors. Transistors were invented in 1947 by Bell Labs. A second reference to the manufacture of transistors during WWII is made in section 2 trade secrets. What kind of research did the author make for this book?
Review of advance copy received from Goodreads Giveaways
Interesting history and fascinating book.
June 24, 2026
This is so beautiful, I love your book!
June 26, 2026
This book is epic. So much research went into it and it's still such a great story. Highly recommend!
July 14, 2026
Best read of the summer.
Displaying 1 - 13 of 13 reviews