Venona. Partial decryption of 4 August 1944:
"As regards the technique of further work with us JURIST said that his wife was [B% ready] for any self-sacrifice[;] he himself did not think about his personal security, but a compromise[PROVAL] would lead to a political scandal and [B% the discredit] of all supporters of the new course[o], therefore he would have to be very cautious. He asked whether he should [5 groups unrecovered] his work with us. I [O% replied] that he should refrain. JURIST has no suitable apartment for a permanent meeting place[;] all his friends are family people. Meetings could be held at their houses in such a way that one meeting devolved on each every 4-5 months. He proposes infrequent conversations lasting up to half an hour while driving in his automobile."
Everything else sent to Moscow with White as a source can be explained away as relatively normal wartime inter-allied chit-chat--the kind of thing that Harriman would have told to every British official he came across in the course of a day. This is much more damaging.
It is *possible* that this cable misrepresents the conversation because the NKVD agents wanted to pretend that they had more sources than they did, and so misrepresented friendly people interested in U.S.-Soviet cooperation as their spies.
It is *possible* that Harry Dexter White thought that he was just being a friendly person interested in U.S.-Soviet cooperation--and then suddenly realized when this conversation began that they thought he was their agent, under NKVD discipline, and was trying to wriggle out--stressing that the Russians would not want to try to expose him as a spy if he didn't cooperate because it would discredit the entire New Deal.
But these possibilities are of the same order of magnitude as that a reasonably well-read disbeliever in Nazi gas chambers will turn out to be an apolitical liberal...
:-(
Brad DeLong