If you ask citizens on the streets what territories the former Russian Empire lost after the revolutions of 1917 and the Civil War, then Poland, Finland or the Baltic states are most often remembered. Less commonly - Bessarabia, annexed by Romania. Transcaucasia, however, sounds extremely rare, despite considerable territorial losses in favor of Turkey. The city of Kars went to the Russian Empire under the Treaty of San Stefano and was part of it for four decades. Until now, in those places you can find many houses, which in Russia are usually called pre-revolutionary buildings. Even the structure of the windows is more typical for the traditionally Russian, although politically this region has not been Russian for almost a hundred years.
According to the Treaty of Brest-Litovsk with Soviet Russia, and then according to the Treaty of Kars with the republics of Transcaucasia, the entire region withdrew to Turkey, and this territory was immediately captured by her troops. Even earlier, the Armenian population was mostly expelled, and its cultural heritage was destroyed. To this day, the ruins of Armenian temples can be clearly discerned among the local landscape.
Why did it happen? First of all, because the Turks, before the Russians, managed to overcome the chaos that arose after the First World War and the collapse of the empire. Having crystallized as a nation and built in the shortest possible time capable institutions of a new state, Turkey received a historical advantage over Russia, which it immediately realized. For Soviet Russia, at that moment, it was critically important to get a calm border in the south and break the diplomatic blockade. Losing a distant area seemed like an acceptable exchange. By the way, Armenia was weakening along the way, whose elite had recently been actively striving for independence.
Assigned territories are highlighted in light gray
Later in Soviet historiography, they did not like to remember this concession. After all, if the losses in the west could be explained by the intrigues of Germany and the Entente, then Kars and the adjacent territories, it seems, gave it up themselves. And there is no point in grieving that the honeymoon of Soviet Russia and Turkey ended so soon. After all, there are no eternal friends and eternal enemies in politics. There are only eternal interests.
By the way, the story of Kars might not end there. In 1946, Stalin planned to punish Ankara for allowing German ships to enter the Black Sea during the Great Patriotic War and other equally dubious actions. The Georgian and Armenian SSR put forward territorial claims to Turkey, which provided for the return of the lost lands with interest. To confirm the seriousness of their intentions, units of the Soviet army began to advance to positions in the Transcaucasus and Northern Iran. In parallel, there was a similar movement in Bulgaria, from whose side it was supposed to march to Istanbul, in which, following the results of the invasion, it was supposed to set up Soviet military bases.
Turkey, which did not have a single chance against the USSR, did the only thing that was left for it - raised a diplomatic noise, hoping for help from Britain and the United States. The calculation was fully justified. Frightened by the unprecedented increase in the power of the USSR, the Western allies were ready to use a nuclear bomb against the Soviet Union, and Moscow had to abandon its intentions to return the lost part of Transcaucasia.
In 1953, the USSR dropped its claims to Kars. Turkey by that time had already been a member of NATO for a year. Modern Armenia does not recognize the Kars treaty, and Georgia denounced it after the Ajarian crisis of 2004, when Turkey threatened to send troops to Batumi, relying on this document.