Seeing the many divisions in the Soviet Union what determained what nationalities got to be an SSR and what became ASSR or smaller divisions. For instance the Tajiks were an ASSR in the UZBEK SSR. Why did they get to be an SSR?
I ask as the SSRs got to be independent states.
One thing I can tell you is that Stalin intentionally gerrymandered the borders of the Kyrgyz, Tajik, and Uzbek republics. Look at a map of the the Fergana region where the 3 republics are drastically tangled up. Before the Soviet Union came along, Tajiks lived all through Uzbekistan (mostly in the cities), and Uzbeks also lived in Tajikistan, etc. The riduculous borders in Fergana are completely arbitrary, having no correspondence to the actual populations before the lines were drawn.