In the first “rabbit hole” post, I suspected that Lionel Ryder, Secretary to the U.S. Envoy to Brazil, fell into a Japanese honeytrap. When I went to the National Archives in D.C., I had two questions. First, who was the Japanese chargé d’affaires for Brazil in 1922. Second, was there any investigation by the Naval Attache office in Rio de Janeiro related to Lionel’s suicide.
I contacted several people from Japan and Brazil before stumbling upon the answer to the first question. I contacted Rogério Dezem-sensei from Osaka University. His expertise is in Japanese immigration to Brazil. With his help and records from the NARA, I identified the chargé d’affaires was 堀口九萬一 (Horiguchi Kumaichi). According to Jamie Bisher, Horiguchi was embroiled in another high level, political assassination attempt involving Korea in 1895. The U.S. Naval attache reported Horiguchi left Brazil in 1923. So, Horiguchi Kumaichi was the answer to the first question.
As I searched for investigative reports within the Rio De Janeiro files, I did not get an answer to my second question. As I posited, I believed the code compromised related to the death of Lionel Ryder and Iwo Horiguche (likely 堀口), a possible Japanese Honeytrap. In 1925, the U.S. Navy released an assessment of the cryptographic compromise, which included the likely source. As can be seen, the compromise was believed to have originated in Germany and not Brazil. As a result, the Lionel Ryder suicide is still a mystery.
Since this was a rabbit hole, I probably will not revisit this research. I am heavily focused on the 1917/18 National Amateur Hockey League research. I did photograph several documents related to Brazil including Japanese immigration and Amazonian insurrection. However, I hope to convey the difficulties of focusing research activities when there are so many interesting facets to explore.
Images of the Navy cypher compromise assessment (Office of Naval Intelligence, Secret-Confidential Files of the U.S. Naval Attache, Rio De Janeiro, Brazil 1919-29,US National Archives, RG 38, Entry 190):
1. Honey Trap: https://en.wikipedia.org/wiki/Honey_trapping
2. chargé d’affaires: https://en.wikipedia.org/wiki/Charg%C3%A9_d%27affaires
3. Horiguchi Kumaichi: https://ja.wikipedia.org/wiki/堀口九萬一
4. Rogério Dezem: https://osaka-u.academia.edu/RogerDezem
5. Jamie Bisher, Intelligence War in Latin America: https://www.amazon.com/gp/product/B01CPS51BM/ref=dbs_a_def_rwt_hsch_vapi_taft_p1_i1
6. Critique of Bisher: https://networks.h-net.org/node/12840/reviews/2081239/hall-bisher-intelligence-war-latin-america-1914-1922