So I'm reading about the Terror/Stalin's purges/etc and the book mentions that, when it was thought that Moscow would be taken by the Germans, the NKVD burned a lot of their records or shipped them deeper into Russia, presumably to keep word of what they were doing from the wider world. This is on top of stories about how guards would execute prisoners out in the wilderness and return with their fingers to enter the finger prints into their files and how the camp doctors would falsify the records of those who were worked to death to show that they had died of more prosaic, natural causes rather than those of malnutrition and exposure.

So my question is...why did they keep these records at all? I mean, I understand that they probably weren't planning to have their country invaded and all that, but what purpose did it serve if Stalin seemed to execute the executioners to keep them quiet and the NKVD did their best to keep the rest of the world from finding out?

Not sure if this is a question that can be answered definitively or from a historian's perspective, but I'd be interested to see if there was ever thought on this subject.

(I guess the same question could be asked about the Nazis and the Holocaust too. If I'm not mistaken the Nazis kept extensive records of their activities.)

So my question