George H. Kerr took some role in this U.S. effort. Kerr had conducted research with SIRI (The Scientific Investigations of the Ryukyu Islands), a joint academic-military effort. Kerr expressed concern about the Okinawan desire to "revert" to Japanese control. Hidekazu Sensui quotes from a 1952 SIRI progress report in which Kerr worries that this movement "constitutes a threat to our position in political warfare" (qtd in 40). As part of the U.S. occupiers' efforts to distance Okinawans from the Japanese, Kerr was asked to write a history of the Ryukyus that would be translated into Japanese.
The English book was written, as Kerr notes in a foreword, "at the request of Brigadier General James M. Lewis, Civil Administrator for the Ryukyu Islands, who desired a text suitable for translation into the Japanese language for use at the University of the Ryukyus" (ii). Kerr's 1953 book, Ryukyu: Kingdom and Province Before 1945 (available on archive.org) became the basis for Ryukyu no Rekishi.
In his short biographical essay about George H. Kerr (pdf), Tony Jenkins notes that
Okinawans of a certain generation variously celebrate or scorn George Kerr's Ryukyu no Rekishi (1956), which they were required or encouraged to read in their college days. It was, and still is, seen either as welcome international recognition of Okinawa's place in history, or as American propaganda, occasionally erroneous, that sought to divorce the 1950s Okinawan collective mentality from Japan. (3)It would perhaps be understandable if the history of the Ryukyus that Kerr was writing was meant only for American civil administration. The fact that the U.S. Civil Administrator saw a need to have an American write a history of Ryukyu to be translated into Japanese was cause for suspicion among Okinawan academics, as Jenkins notes.
But Jenkins also argues that Kerr was at least somewhat aware of the complicated nature of Okinawan-Japanese relations--Kerr saw the Okinawans as needing to emphasize a more equal status with the Japanese mainland so that when Japan retook control of the islands, they wouldn't be treated as second-class citizens. This theme is also evident in the foreword to Ryukyu, where Kerr argues that "the people of Ryukyu are much more eager to be recognized and accepted as 'Japanese', than the people of Japan are ready or eager to claim them without reservation." He concludes,
Okinawa and its people have sometimes been likened to Texas and the Texans. They are proud of their tradition of former independence, and cherish special cultural characteristics which set them apart and give them self-respect. But like the Texans whose pride and patriotism as citizens of the United States should not be challenged, the people of Ryukyu consider themselves patriotic and true citizens of the larger unit, Japan. The attitude of the sophisticated Japanese of Tokyo toward the farmers and fishermen of Okinawa Province finds its parallel in the attitude of the native New Yorker toward the drawling, ranch-born cowhand on the most distant border ranges. With great reluctance the Okinawan will admit that the record shows Japan's discrimination in economics, politics, and social advantage. Nevertheless, the ties of race, common language, education, political and administrative institutions, and economy were and may be assumed to be permanent. (ii)It would be interesting to know if any of these thoughts made it into the Japanese translation, though. Here's an interesting case where any changes between the English and Japanese versions would be a result of the U.S. civil administration's censors rather than "cultural" differences or censorship by the Japanese themselves.
[Update: Prof. Sensui noted on Facebook that the Japanese translation of the book included the foreword, which was "often quoted by Okinawan writers and politicians (Prof. Ota's was one of the earliest cases), though they usually skipped the part in which GHK drew comparison with Texans."]