Paper short abstract:

Based on documents in Swedish archives that so far have not been taken into account by researchers, this paper deals with collaboration between Swedish military intelligence and Japan's military attaché in Sweden during WWII, Onodera Makoto.

Paper long abstract:

Japan's military attaché in Sweden during WWII, Onodera Makoto (1897-1987), is a modern-day hero in the eyes of many Japanese. Arriving in Sweden in early 1941, Onodera was an intelligence officer whose accomplishments made him instantly famous, when they became known to the Japanese public in 1985, with the memoirs of his wife, Yuriko, and a documentary about Onodera on the NHK television channel. His fame rests not only on the fact that he was a skilled intelligence officer but also that he was a key person behind a famous peace feeler that involved King Gustaf V and other Swedish royalties.

A key task of a military attaché is to provide intelligence for his home base. Information is obtained in many ways, espionage, HUMINT, OSINT, collaboration and exchange with officials of the host country and intelligence officers of other countries posted in the host country, etc. Based on documents in Swedish archives that so far have not been taken into account, this paper deals with an area where hardly any research has been presented, the extent to which collaboration and exchange took place between Onodera and Swedish military intelligence. It is shown how the Swedes pursued a two-thronged approach to Onodera, one involving the chief of the C-Bureau, Carl Petersén, and Onodera; and the other involving "X" representing the C-Bureau and "Y" representing Onodera. At the same time exchange was used in deception operations targeting Onodera that Petersén and the C-Bureau were involved in.