Wow. Thanks for that, I'm glad you brought him up.
There's a whole chapter devoted to Owen Lattimore in "Blacklisted by History" and I'll share with you some of the highlights.
Overall, McCarthy fingered Lattimore as a key Soviet agent but then backed off. McCarthy claimed Owen was responsible for the US State Department pro ChiCom stance at a time when Chiang Kai-shek needed the assistance of the USA. The Tydings Hearings apparently exonerated Owen including a Tydings implication that the FBI agreed that Owen was beyond reproach. However, Much like everything else around McCarthey, history and facts have not been kind to Progressive world view.
While Owen is not mentioned in Venona Cables as an asset, here's what we discover.
First, Tydings outright lied about the FBI's and Hoovers stance on Lattimore. In a recently released memo from April 1950, Lou Nichols states, "he couldn't understand what had come over Sen Tydings, as he recalled very distinctly that the Director had been asked the question as to how he would regard Lattimore's loyalty, and the
Director stated that if her were on the Loyalty Board he would question it; further the Director had also regarded Lattimore as a security risk
What type of man was Progressive Hero Owen Lattimore. Apparently, according to Evans he "Seldom met a Red atrocity he couldn't like or find an excuse for." While touring the notorious Magadan-Kolyma Siberian Death Camp he remarked "instead of gin, sin and brawling of an old fashioned gold rush, extensive greenhouses growing tomatoes, cucumbers and melons to make syre hardy miners get enough vitamins"
Here's what Wikipedia said of Lattimore's workers paradise
"
The Arctic Death Camps
In 1937, at the height of the Purges, Stalin ordered an intensification of the hardships prisoners were forced to endure.[4] Aleksandr Solzhenitsyn quotes camp commander Naftaly Frenkel as establishing the new law of the Archipelago: "We have to squeeze everything out of a prisoner in the first three months — after that we don't need him anymore." [5] The system of hard labor and minimal or no food reduced most prisoners to helpless "goners" (dokhodyaga, in Russian).
Robert Conquest, Yevgenia Ginzburg, Anne Applebaum, Adam Hochschild and others (see bibliography) describe the Kolyma camps in some detail. The suffering of the prisoners was exacerbated by the presence of ordinary criminals, who terrorized the "political" prisoners. Death in the Kolyma camps came in many forms, including: overwork, starvation, malnutrition, mining accidents, exposure, murder at the hands of criminals, and beatings at the hands of guards. A director of the Sevvostlag complex of camps, colonel Sergey Garanin is said to have personally shot whole brigades of prisoners for not fulfilling their daily quotas in the late 1930s.[6] Escape was difficult, owing to the climate and physical isolation of the region, but some still attempted it. Escapees, if caught, were often torn to shreds by camp guard dogs. The use of torture as punishment was also common.
Soviet dissident historian Roy Medvedev has compared the conditions in the Kolyma camps to Auschwitz."
Kolyma - Wikipedia, the free encyclopedia
Also, a May 1941 FBI custodial detention notice obtained for Owen under FOIA and reproduced in "Blacklisted" describes the "Professors 'nationalistic tenancies' as 'Communist'"
Yes, Owen Lattimore was not mentioned in Venona, but Hoover didn't trust him and he sure loved everything about the USSR and the Chicoms.