Why did the soviet union feel like it had to take control of the eastern european nations of east germany, poland, czechoslovakia, romania, hungary, and bulgaria?

why did the soviet union feel like it had to take control of the eastern european nations of east germany

operation overlord was the codename for the battle of normandy, the allied operation that launched the successful invasion of german-occupied western europe during world war ii. the operation was launched on 6 june 1944 with the normandy landings

these civilizations were located around fertile rivers, where they could produce an abundance of crops