So I'm reading a book right now about Armenia and the author said that the USSR "gave" Nagorno-Karabakh to Azerbaijan. I also read that Donetsk was given to the Ukraine. I think South Ossetia was given to Georgia.
Each of these "gifts" created massive problems later both for Russia and for the other countries. Ethnic cleansing and war with Armenia and Russian invasions of South Ossetia and Donetsk.
So my question is, why did the USSR do this? Did they not consider ethnicity to be a problem in these areas? If they are all one country, why did these borders between the Soviet republics matter? Were they economic decisions? Political rewards for compliant local officials? Efforts to buy loyalty? Finally, what is the history of this policy? Was it Stalin? Kruschev or later Soviet heads who promoted it?
Thanks.
Part I
Expanded from an earlier answer
The administrative division of the Soviet state during the 1920s was the intersection of both expediency and the Bolshevik's own, sometimes rather hazy, ideological position on the nationalities question. The groundwork for these policies had been laid during the closing stages of the Russian Revolution and the opening phases of the Russian Civil War. Both the lesson of Finland, which used the Revolution as a pretext to leave the emerging revolutionary state, and the near lesson of the Ukraine had taught Lenin and company the importance of not ceding too much independence to these provinces lest Moscow lose control. Yet, the Bolsheviks also recognized that promises of national autonomy in a new republic had a powerful appeal among the former empire's diverse peoples. The end of the Civil War in 1922 also created a vexing problem for the Bolshevik leadership in Moscow in that they needed a formal state structure. It as clear by then that world revolution was somewhat more distant than in 1917, so the new Soviet state had to delimit the administrative boundaries and exact division of political power in the Soviet state to keep the flame of revolution alive.
This type of administrative division was a tall order for such a heterogeneous polity as the Soviet Union, which had no single ethnic majority that had a plurality. Great Russians consisted of approximately 44% of the empire according to the 1897 census, which was the last accurate data set of the empire's population prior to the First World War and even though the census is something of a blunt analytical instrument, it does show there was no dominant ethnic group. Moreover, for all of their faults, the early Bolsheviks were somewhat serious about rectifying or eliminating Great Russian chauvinism. Part of this was a tactical move from the Civil War as a means to attack the Whites and further denude them of support, but this anti-Great Russian nationalism stemmed from deeply ingrained political culture that associated Great Russian nationalism as one of the tools of the Romanovs. As good Marxists, the Bolsheviks felt that nationalism was too often a tool of the ruling classes to divide the working classes, but they faced the vexing problem that nationalism continued to exist even after the Revolution.
One of the guideposts for the Bolsheviks' nationality policy was 1913's Marxism and the National Question written by Stalin. The previous year, members of the Socialist Revolutionary Party had endorsed an Austromarxist solution to the the nationalities issue. Formulated by Otto Bauer and Karl Renner, Austromarxism upholds the principle of national personal autonomy, a rather nebulous term that basically means that an individual has a right to declare their own nationality and would join in a federation of their respective national Marxist party. In August 1912, Austromarxism had received a significant boost when the Menshevik wing of the Social Democrats (SD) meet with the Bundists (a Jewish socialist labor group) and endorsed an Austromarxist solution for the Russian empire after the eventual revolution. Lenin, as a leader of the Bolshevik SD faction, saw it was essential to combat Austromarxism and differentiate the Bolsheviks from the larger movement. Lenin tasked Stalin to come up with an official position on the nationalities issue; one that would be congruent with Marx, serve the needs of revolution, and condemn the Bolsheviks' ideological rivals. Stalin's Georgian background added a non-Russian luster to this position paper. Lenin wrote to Gorky "we have a marvelous Georgian who is busy working on a long article 'illuminating' the proletarian solution to the national problem."
The resulting paper was the famous Marxism and the National Question attacked the principles of national personal autonomy and Austromarxism as a deviation away from Marx. The fundamental difference between the Bauer/Renner paradigm and Stalin's was that Stalin strongly asserted that a nation needs a territorial basis and must reside within a given territory and have a historical claim to that area. Austromarxism was thus a retrograde step according to Stalin as it diffused the strength of a Marxist political movement and would hamper the ultimate goal of Marxism after a revolution: the creation of a new socialist consciousness based upon class, not bourgeois concepts like nation.
The rub for all this is that the Bolsheviks seldom had any clear and coherent policy with regards to the national question prior to 1917, much of it was ad hoc and conditional. Stalin would at various points between 1913 and 1917 push a quasi-Austromarxist solution and Lenin was really ambivalent about Marxism and the National Question's paeans to national culture on the basis it was too bourgeois. But it proved an ideal solution to for the post-1922 environment. Moscow would delimit the borders of the nascent Soviet state based on the perceived historic territory. Areas with a large, preexisting ethnic bodies with already defined national culture tended to become SSRs and smaller ones became Autonomous Soviet Socialist Republics (ASSRs), but the Soviet state also made provisions for those areas with large minorities, which was the case of Nagorno-Karabakh, which became an autonomous region (oblast) or groups with a smaller population which became smaller autonomous territories (okrugi) that existed within these SSRs.
It is important to keep in mind that this territorialization of ethnicity was intended to be temporary over the long-term, but instead was to be a way-station towards the creation of what was at the time termed the New Soviet Man. The Soviet project intended for national particularism to be gradually subsumed into a new Soviet identity that would emerge out of the project of building socialism. Ideally, the New Soviet Man would emerge from the shopfloor, but the vast territories of the USSR made this unworkable for the entire population. The Communist Party (CPSU) thus emerged as one of the primary tools to reach the masses. The 1920s was the heyday of Korenizatsiia (indigenization, memorably termed by Terry Martin "Soviet Affirmative Action") policies that promoted native cadres within the local CPUSA. Lenin and the other Bolshevik leaders were ambivalent about Russification and the promotion of Great Russians at the expense of other peoples. There was a fear that if the new USSR could fracture if it repeated the mistakes of tsarist Great Russian chauvinism. To counter this, the state also promoted the local languages, cultural programs, and most important for Moscow, the strengthening of the local Communist Party establishments.
The territorialization policies were not without their problems. Moscow's definition of both "nation" and its "natural" territory were often quite arbitrary and seldom reflected the complexities of national identity in such a vast and heterogeneous polity like the Soviet Union. When dealing with defining non-European populations, Soviet planners in Moscow often relied upon tsarist-era ethnography and Marxist conceptions of universal human development led to the internalization of imperial mentalities. And the centre often twisted the nationalities policy to meet the wider geopolitical imperatives of the state. For example, the Soviet regime tended to perceive ethnic Poles who refused to assimilate to the new ethnic republics (largely Ukraine and Belarus) as either potential agents or dupes of the Polish anticommunist state. Stalin's flexibility towards the geographic boundaries of Poland was an expression of this etatist interpretation of Soviet nationalities. He would justify the western shift of Poland as just correcting Poland to its natural historic boundaries and away from "ancient Slavic soil," and population transfers (aka ethnic cleansing) as an extreme, but logical, application of Marxism and the National Question.
To destabilize them. Their general goal was to have large pockets of minorities in neighbouring republics. Go look at the map and see how ridiculous the borders look.