Why did stalin feel compelled to create puppet states in eastern europe?

The Nazi invasion of the Soviet Union and the development of the astonishing "Blitzkrieg"  (a violent surprise offensive by massed air forces and mechanized ground forces in close coordination, according to the Merriam-Webster Dictionary) by German units on June 22, 1941 was a surpirse for Stalin and the Soviet leaders. Not because the Soviet dictator did not believe that a German invasion would materialize, but because he had calculated that Germany was not prepared to invade the Soviet Union at that moment. Unlike the mercurial and unpredictable Nazi dictator Adolf Hitler, Stalin was given to cold and emotionless calculations. The German undeclared attack left a deep wound in the Russian psyche; the collective memory of the invasion instills fear of a repetition. So, setting up buffer states in Eastern Europe contributed to a sense of Soviet security after WWII.

Explanation:

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