The USSR
russia
All of Eastern Europe.
joesph Stalin
The Soviet Union
Through 1944 that would be Germany, after that Russia controlled and held eastern Europe for decades.
Russia has historically controlled various territories, including its current borders along with parts of Eastern Europe (such as Ukraine, Lithuania, Latvia), Central Asia (such as Kazakhstan, Uzbekistan), and parts of the Caucasus (such as Georgia, Armenia). Additionally, Russia has also exercised influence over other countries within its sphere of influence, such as Belarus and Moldova.
Communist
because Adolf Htler wanted to control all of Europe.
Because the Soviet Union controlled Eastern Europe for four decades. This changed when they elected a new leader, Mikhail Horbachev, he gave Eastern Europe more freedom as one of his reforms.
Not sure but if I had a guess it probably was the soviet union (russia)
Japan, Yes but not Easter Europe. Eastern Europe was controlled by the communist USSR. The USA only held up to West Berlin.
Soviet Union