Part I, in yesterday's post, is also interesting. In it he discusses the Sov's murky relationship with Japan.
I recall one of the Doolittle Raiders landed near Vladivostok because of some fuel problem making it certain they would not get even close to China. The Sov’s interned them for over a year, eventually sending them to a town near Iran. IIRC, there has always been some controversy as to whether the Sov’s “allowed” them to “escape” to avoid officially repatriating them.