Mr Khan said: The inability of the Soviet Union to stamp out ethnic identity (or at least melt it away like we largely have in America, where a White American would primarily identify himself as such, as opposed to a Soviet citizen who was very much still a Russian, Kazakh, Lithuanian, Ossetian, etc) played a part, since the country was relatively easy to divide along ethnic fault lines |
Russian isn't ethnicity. Your quote is like saying "furniture, chair, table, sofa". It's effectively was playing the same role as American in pre-Soviet era in this part of the world. But I understand the confusion, it's may seem like ethnicity after some 1200 years of history for a foreigner.
National policy is indeed the weakest point of Soviet internal policy in general (outside Iosif Vissarionovich, maybe), but for a completely different reason.