外国的百科上有答案:
The region was added as a semi-exclave to the Russian SFSR; since 1946 it has been known as the Kaliningrad Oblast. According to some historians, Joseph Stalin created it as an oblast separate from the Lithuanian SSR because it further separated the Baltic states from the West.[44] Others think that the reason was that the region was far too strategic for the USSR to leave it in the hands of another SSR other than the Russian one.[41] In the 1950s, Nikita Khrushchev offered the entire Kaliningrad Oblast to the Lithuanian SSR but Antanas Sniečkus refused to accept the territory because it would add at least a million ethnic Russians to Lithuania proper.[32][45]