Spies sent from Japan helped set the stage for the attack on Pearl Harbor. That’s what I learned in reading about the event over the years. But what none of these accounts revealed was that Nazi spies in Hawaii played at least an equally important role in guiding the Japanese Imperial Navy to the ships in the harbor and the airfields inland. (If German spies were even mentioned, it made no impression on me.) And now, after thirty years of on-again, off-again research into long-hidden family secrets and FBI records, an American journalist tells the story of her grandfather, his wife, and their daughter in supplying the Japanese with what they needed to know to destroy the US Pacific Fleet. And her grandfather, she learned, “was the only person tried and convicted for the bombing of Pearl Harbor.” This is the extraordinary story she tells in Family of Spies.
A compelling account that leaves the reader breathless
In her tell-all book, Kuehn skillfully interweaves an account of her decades-long quest to learn the truth of her family’s role in Hawaii with a blow-by-blow tale of their activities on the island of Oahu. It’s clichéd to write that a book reads like a thriller, but this one does. Kuehn doles out her discoveries as they came over the years, drip by drip. One surprise follows another. And in the end, the Nazi officials and Japanese spies and FBI agents who all play roles in the story of Otto and Friedel Kuehn and their children remain fixed in memory.
Family of Spies: A World War II Story of Nazi Espionage, Betrayal, and the Secret History Behind Pearl Harbor by Christine Kuehn (2025) 247 pages ★★★★★
A Nazi saga shaped by World War I
The German Empire’s defeat in World War I weighed heavily on young Otto Kuehn, as it did for so many other veterans. Right-wing propaganda fostered by General Erich von Ludendorff convinced millions of Germans that their army hadn’t lost the war. The socialist government and the Jews had betrayed them. This set the stage for the rise of Adolf Hitler and the Nazi Party. And young Otto had found his calling. Joining early, he quickly rose in the ranks.
Eventually, in 1931, he faced off against Reinhard Heydrich as a candidate to organize a network of spies, the precursor to the Gestapo. Heinrich Himmler, Reichsführer of the SS, awarded the job to Heydrich, who quickly set out to eliminate Otto. But Otto’s teenage daughter, Ruth, was Joseph Goebbels‘ mistress at the time—before he learned she was half-Jewish. To save her from imprisonment in one of the new concentration camps. Goebbels dispatched Otto and his family to Hawaii to spy on behalf of Germany’s Japanese ally. “The Japanese paid [Otto] an enormous salary, $2,000 per month (about $44,000 in today’s dollars), to spy on Pearl Harbor, with its destroyers, battleships, and anti-aircraft batteries, in preparation for the eventual attack.” Otto, Friedel, Ruth, and their two younger sons, Eberhard (the author’s father) and little Hans, sailed for New York, crossed the USA to California, and shipped to Honolulu.
They left their eldest son, Leopold, behind in Berlin. He was a committed Nazi and a rising force in the SS. a high-ranking member of Goebbels’s staff in the Ministry of Propaganda.
Five years as spies for the japanese
Once in Hawaii, Otto, Friedel, and Ruth set out to befriend American naval officers and establish themselves in Hawaiian society. They made a big splash, buying several large homes and entertaining lavishly, much to the chagrin of their handlers in Tokyo. After a time, the payments from Japan became spotty, once even forcing Otto to take a menial job to support the family. Meanwhile, he, Friedel, and Ruth all actively gathered information for the Japanese. But Otto and Friedel’s work for the Japanese paled beside Ruth’s. As the author notes, she came across her sweet aunt in a book titled “The World’s 30 Greatest Women Spies. There, in black and white, right next to Mata Hari, was Aunt Ruth.”
For five years, the family tallied the comings and goings of US warships at Pearl Harbor and took photos of both naval and US Army Air Force fields inland. (The two boys knew nothing of this.) Otto developed an elaborate system to transmit the information to Tokyo via the Japanese consulate and in trips to Japan.
Then, as plans for the attack progressed, the Imperial Navy sent an outstanding young naval intelligence officer, Takeo Yoshikawa, to Hawaii. He met with Otto but conducted his own reconnaissance of the American military presence on Oahu. (It’s Yoshikawa who is most prominently mentioned in most accounts of Japanese espionage in the islands.) Two senior Japanese consular officials were more actively involved in communicating with Otto.
More about the book
Since I’ve long since learned that AI can do a better job summarizing a book than I can, I turned to the chatbot Claude (Sonnet 4.5) for help. What follows is its account, word-for-word, except that I’ve inserted subheads and deleted the few links to its sources.
A gripping true story
Family of Spies is a gripping true story that begins in 1994 when Christine Kuehn received a mysterious letter from a screenwriter asking about her family’s connection to World War II and Nazi espionage. When she confronted her elderly father, Eberhard, about the inquiry, he broke down in tears, revealing a devastating family secret he had kept hidden for decades.
The book chronicles the shocking story of Christine’s grandfather, Otto Kuehn, who was the only person tried and convicted for his role in the bombing of Pearl Harbor. The Kuehn family was a prominent Berlin family that embraced the rise of the Nazi Party during Germany’s economic hardships in the 1930s. The family’s trajectory changed dramatically when Christine’s aunt Ruth began an affair with Nazi propaganda minister Joseph Goebbels.
From Joseph Goebbels’ mistress to spy in Hawaii
When Goebbels discovered that Ruth was half-Jewish, he faced a dilemma. Rather than having her killed, he sent the entire Kuehn family to Hawaii to work as spies, establishing an intricate espionage operation from their home just miles from Pearl Harbor. From this strategic location, the family gathered and transmitted critical intelligence to the Japanese military, providing information about American naval ships and their defenses that proved crucial to the devastating December 7, 1941 attack.
The narrative alternates between two timelines: Christine’s thirty-year journey of discovery as she researched her family’s dark past, and the historical events themselves, detailing the spy operation in Germany, Japan, and Hawaii. After Otto Kuehn was arrested and convicted, young Eberhard faced an agonizing choice. As a teenager, he courageously rejected his family’s legacy, refusing to return to Germany and instead declaring himself an American. At eighteen, he joined the U.S. Army and fought at Okinawa.
Both a historical investigation and a deeply personal memoir
Written with the skill of a seasoned journalist, Kuehn’s debut book reveals previously hidden details about the Pearl Harbor attack while exploring profound themes of family loyalty, betrayal, and moral courage. The book examines how ordinary people can become caught up in totalitarian movements and the lasting impact of these choices across generations. It’s both a historical investigation and a deeply personal memoir about confronting a painful family legacy and the importance of truth-telling, even when that truth is uncomfortable.
About the author
On the anniversary of Pearl Harbor on December 7, 2025, CBS News ran a fascinating story about Christine Kuehn and the secret about her family that she and her husband had buried in their basement for years. Then “she finally decided to write a book about her Family of Spies.” As she told the network, “I stopped and started so many times because, you know, I was having trouble accepting what I was learning . . . My grandfather was the only person tried and convicted for the bombing of Pearl Harbor.'” The backstory, and complete details, are in her bestselling book. And, as Google Books notes, “Following a career in journalism, public relations, and nonprofits, Christine now lives in Maryland with her husband, close to their three grown children.”
For related reading
You’ll find related books at:
- 10 top WWII books about espionage
- Good nonfiction books about espionage
- 10 top nonfiction books about World War II
- Books about World War II in the Pacific
- Two dozen excellent memoirs
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