Should also mention that— included in the murdered Russian POWs was the commander of the White Russian Cossacks: Peter Krasnov Lt. Cmdr Don Cossaks and 5 other White Russian commanders Vyacheslav Naumenko, Timofey Domanov, Sultan Kelech Ghirey, and Andrei Shkuro of the Kuban Cossack.
The Commies followed up on them after all that time, through WWII. Tolstoy does note that Churchill unlike the stupid OSS Americans in Ukraine (come to think of it- did that include at that time William Barr’s father? Hmmm), held back quite a lot of White Russians/anti-communists for their deployment in post war Russian satellite states in Brit Intel (this fact may or may not have been shared with American OSS but probably did make it through to Philby and thus— they were still taken out).
Long memories and persistence: the NKVD murdered the Welsh journalist Gareth Jones who slipped into the Ukraine and reported (through NYTimes rival paper baron William R. Hearsts papers) on the truth of the Holodomor. Gareth Jones outed the criminal Pulitzer winner Walter Duranty (who was parenthetically a real pervert whom Lenin/Stalin controlled by blackmail and “keeping him happy in his pleasures”) who lied in every way about the Holodomor and the Soviet Union. A propagandist for Stalin employed by the NYTimes— who would have thought that...... heh.
James Bond film GOLDENEYE does mention Cossacks as well... Rogue British agent Alec Trevelyan has to be stopped by Agent 007...Trevelyan's parents were Cossacks who were sent back to USSR by British after WW2...Trevelyan wanted some revenge for what British government did.