In this article I gave that introduces this metric, it has some explanations as to why they think this is a reasonable metric, though I don’t think that it directly corresponds to “net resources”. I think the point is that having a larger population to take care of requires more resources, hence making it more difficult to project global power, when comparing 2 countries with similar resources.
As far as I understand, It is the GDP (of a country) times the GDP of that country per capita, and then normalized. For example ChinaGDP * ChinaGDP/Chinapopulation is 10 times smaller than USGDP * USGDP/ USpopulation. This paper argues this is a better predictor of power projection.
Not exactly answering your question (I know nothing about Kazakstan in particular), but AES the podcast had an episode on the aboriginal people of the USSR, where they interviewed two canadian scholars who wrote a book “When the North Was Red: Aboriginal Education in Soviet Siberia”. It was in two parts, part 1 and part 2. This can offer an interesting perspective on the rights of indigenous peoples and maybe some glimpse on treatment of minorities in the USSR.
What would happen if capital succeeded in smashing the Republic of Soviets? There would set in an era of the blackest reaction in all the capitalist and colonial countries, the working class and the oppressed peoples would be seized by the throat, the positions of international communism would be lost.
Joseph Stalin
I think their criticism is based on idealism. They claim (unsure whether sincerely or not) that we categorically consider western powers as uniquely evil (or that we axiomatically consider that). They fail to see that we recognize the western powers as uniquely evil in the particular historical context of actual existing capitalism, colonialism, and imperialism.