Purges, not historical catastrophe, created Soviet society’s unprecedented atomization.

Evidence

In the last analysis, it has been through the development of this device to its farthest and most fantastic extremes that Bolshevik rulers have succeeded in creating an atomized and individualized society the like of which we have never seen before and which events or catastrophes alone would hardly have brought about. — Hannah Arendt, The Origins of Totalitarianism, 770