German Spies on Oahu in late 1930s

The Far Outliers are back in the Pacific now, as my reading reflects. I've been reading a new book that came out after we left for our academic year in Poland: Family of Spies: A World War II Story of Nazi Espionage, Betrayal, and the Secret History Behind Pearl Harbor (Celadon Books, 2025), by Christine Kuehn, the granddaughter of the family of spies. Honolulu Civil Beat author Kirsten Downey read an advance copy of the book and highlights some of its findings in her online commentary on The Secret Life of a Prominent Kailua Family Revealed. Here are some excerpts.

There were indeed spies among us.

A long-running tale of intrigue in Hawaiʻi will get a new twist later this year with the publication of a soon-to-be published book from inside the family of notorious Hawaiʻi spies. Wealthy German nationals Otto Kuehn and his family were paid by the Japanese government to spy on U.S. military operations at Pearl Harbor, and they funneled information to Japan that helped make the Dec. 7, 1941 attack so devastating.

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In her book Christine — the daughter of Otto’s son, Eberhard — describes the family’s spy history as a secret concealed from the grandchildren. She gradually unspools how she unraveled the story and pressured her relatives into sharing some of the facts, with her own research filling in more of the specifics. Eberhard, sometimes crying, declined to share many details about what his family had done and then developed dementia.

Her account will be new to many people. But the tale has independently survived in Hawaiʻi, amid the whispered reminiscences of kamaʻāina, in published news accounts from the era, inside archival records housed at the University of Hawaiʻi’s War Records Depository and in books about espionage published after the war. It’s been included in a list of the FBI’s most famous cases. All shed more light on how the chain of events unfolded.

Otto Kuehn, a former naval officer in Germany, his wife Friedel and their three charming children made quite a splash in Hawaiʻi in the late 1930s.

Mr. and Mrs. Kuehn had first arrived on the ship Tatsuta Maru in the spring of 1935, stopping in Honolulu for two weeks before heading to Japan, which they visited several other times in the next few years, according to gossipy society news reports at the time.

By 1936, the Kuehns had permanently settled on Oʻahu, where they were mentioned as the hosts of a dance party at the Royal Hawaiian Hotel and as guests at a music recital attended by Hawaiʻi’s elite. He said he was in Hawaiʻi to learn Japanese.

The Kuehns became popular hosts at their posh homes in Kailua and Lanikai, frequently hosting the young naval officers who were squiring Ruth, their pretty 22-year-old daughter, around town and on outings. She and her mother operated a beauty salon near the Kāneʻohe Naval Air Station that was a favorite spot for Navy wives. Their two younger sons, Eberhard and Hans, were students at Punahou.

In August 1941, Ruth, then 25, married a widower, retired stock broker, J. Carson Moore, “who was flattered by her interest,” his family later recalled. Moore, 48, was a generous bon vivant who hosted an open bar at his home, with free-flowing booze, that was frequented by service members. Moore called his little saloon the S.S. Rum, according to archival records at the University of Hawaiʻi.

America was at peace at the time, but the Japanese Empire’s expansionist and militaristic ambitions were drawing increasing concern, particularly as Japan allied itself with Nazi Germany.

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Many details of the Kuehn case were initially concealed because it was a wartime secret, which allowed both Otto and Friedel to vehemently protest that they were innocent of the charges.

In a letter to Otto, Hormann told him they felt misled, because they had considered him “a good Joe,” but that now they had been left hoping “that you were innocent of giving aid to the enemies of our country.”

Otto responded to Hormann in 1947, described the spying allegations as “ugly rumors,” and said his attorney had “demonstrated his innocence.”

“Mistakes will be made in time of national hysteria or danger,” Otto wrote in another letter. He added that his attorney “firmly believes in American justice and is sufficiently confident in a final success regarding my affair.”

In 1962, Friedel sued the U.S. government, saying that the charges against them were “all rot,” and that the allegations were brought against Otto to cover up the incompetence of the American military in allowing the surprise attack to occur. She sought $27,000 in damages from the U.S. government.

The facts, however, when they finally emerged, were damning. The Kuehns had done much more than make friends with amiable American military officers.

Otto had opened a steel furniture company, winning a commission to decorate a cocktail lounge at Pearl Harbor, which enabled him to get access to the base and take photographs of the ships in the harbor. He took pictures of other military installations, including Bellows, Wheeler and Hickam, revealing aircraft configurations. On at least one occasion, Otto took little Hans with him as he conducted his investigations, according to his granddaughter.

A Wikipedia article on the Kuehn family pieces together more sources on the family spy network.