Kaliningrad was (and still is) Russia's only (non-trivial*) exclave. Why did Stalin and the Soviet leaders transfer Kaliningrad to the Russian SFSR rather than the Lithuanian SSR (with which Kaliningrad was contiguous)?
- Soviet leaders believed the Soviet Union would last indefinitely (and so for strategic purposes, it hardly mattered if Kaliningrad was in the Lithuanian SSR or the Russian SFSR).
- They could not have known that a mere half-century later, Lithuania would become Russia's enemy.
- And thus, for administrative purposes, it would surely make sense to have Kaliningrad administered under Lithuania, rather than have an awkward Russian exclave. (We know for example that even Crimea, which is linked by bridge to Russia, would be transferred to Ukraine in 1954 because of "the integral character of the economy, the territorial proximity and the close economic and cultural ties between the Crimea Province and the Ukrainian SSR". This argument, I presume, would've been a fortiori true of Kaliningrad and the Lithuanian SSR.)
But clearly the Soviet leaders did otherwise, so how did their thinking differ from my above thoughts?
*Technically, Russia also has another exclave, namely Sankovo-Medvezhye, which is completely surrounded by Belarus (and is hence also an enclave). However, this second exclave is trivial in that it is (i) unpopulated; (ii) 4.5 km² in size; and (iii) only 800 m away from the "proper" border.