From Family of Spies: A World War II Story of Nazi Espionage, Betrayal, and the Secret History Behind Pearl Harbor, by Christine Kuehn (Celadon Books, 2025), Kindle pp. 119-120:
Special Agent Shivers was convinced the Kuehns were spies; he just didn’t know for whom. The payments pointed to the Japanese, but the FBI was getting information that the Nazis also had an interest in Pearl Harbor. That revelation came from another German spy turned double agent for the British Secret Intelligence Service, MI6: Dusko Popov.
Popov was a well-educated Serbian who attended law school at the University of Freiburg in Germany in 1935. A few years later he was recruited by a former classmate to work for the Abwehr, the German military intelligence service.
Popov immediately contacted the British diplomatic authorities, who enlisted him as a double agent. Within a short period of time, the Germans had come to trust him implicitly, even fronting him $50,000 to set up a spy ring in London. Popov was supposed to turn the money over to MI6, as part of a plan to fleece the Germans out of chunks of cash.
Ian Fleming, a British intelligence officer who would go on to create the character James Bond, was assigned to watch over Popov and make sure the cash made it back to London. After receiving the money from the Germans, Popov met Fleming in Portugal for the trip back to England. The Serbian, a well-known ladies’ man and gambler, made his way to Casino Estoril, an oceanside casino that was a well-known hangout for spies and other international highfliers.
While gambling at a nearby table, Popov overheard a Lithuanian businessman pompously declare he would match any bet, no matter how high the amount. Popov sauntered over to the table, sat down across from the man, and, without saying a word, dropped $50,000 on the table—MI6’s $50,000, the equivalent of $1 million today. The casino went quiet, and Fleming went white watching Popov potentially wreck the entire operation. The flustered Lithuanian asked the casino if they would lend him the money if he lost. Not unexpectedly, they declined, and the man walked away from the table, red-faced. Popov pulled the money off the felt with a grin, loudly proclaiming that gamblers like that are “an annoyance to serious players.”
Popov was, like Otto, a risk-taker, a bit of a narcissist—and Popov was purportedly Fleming’s inspiration for James Bond. The baccarat scene was even re-created, blow for blow, in his first book, Casino Royale.
In August 1941, the Germans sent Popov to the United States with $58,000 and a directive to establish a network of spies. Then he was to head to Hawaii and gather as much intelligence as possible on Pearl Harbor. Unbeknownst to Otto Kuehn, Popov was to be his replacement.
The Japanese had grown tired of Otto’s flamboyant lifestyle and considered him a growing security risk. Frequent phone calls and visits to the consulate, exorbitant spending, wild parties with military officers that made the local gossip column—Otto was becoming a threat to the operation. Fresh blood was needed, and Japanese intelligence asked Goebbels to replace him.
Arriving in New York, Popov set up a meeting with the FBI. J. Edgar Hoover was suspicious of the double agent, agreeing to let his staff meet with Popov only after the British reassured him. Popov was eventually summoned to the Commodore Hotel, where he showed the agents his orders, written in microdots, a new technology invented by the Germans that reduced entire pages of information down to the size of a period.
Almost half the hidden directives consisted of questions the Germans wanted answered about military operations in Hawaii: the depths of the water at Pearl Harbor, the torpedo nets under the water’s surface, exact locations of air bases at Hickam, Wheeler, and Kaneohe, and locations of submarine stations, along with sketches of the Pearl Harbor piers. “Is the Crater Punchbowl being used as ammunition dump?” read one question.
The warning was clear: The Nazis wanted Popov to gather intelligence the Japanese needed for an attack on Pearl Harbor. That got Hoover’s attention, and the FBI director decided to come to New York and meet with Popov personally. But when the two met face-to-face weeks later, the rendezvous was a disaster. The FBI director could barely contain his disdain for the German double agent. “You’re like all double agents,” he berated him. “You’re begging for information to sell to your German friends so you can make a lot of money and be a playboy!”
Popov brushed off Hoover’s comments and reiterated to the FBI director his warning of an impending attack. “But he just wouldn’t listen to anything I had to say,” he said later.
Hoover had deployed a lot of manpower to the FBI office in Hawaii and stepped up the pressure on Shivers. Yet here was the plan for the entire Japanese assault in front of his face, and he ignored it. While Hoover did notify President Roosevelt that the FBI had discovered a new microdot technology, forwarding a small portion of the text from Popov, he sat on the most important information: The Japanese were planning an attack on Pearl Harbor.
The Abwehr, meanwhile, aborted Popov’s mission to Hawaii. The glaring spotlight thrown on him from Hoover would bring too much attention to Japanese operations there. Otto would remain in place as Japan’s spy. But Germany’s role in the Pacific was now obvious. It was working in concert with Japan toward a common goal of knocking out the Pacific Fleet at Pearl Harbor, and they were using a network of spies to do it.
Far Outliers 