Why did the soviet union pursue the domination of eastern europe, including constructing the berlin wall?

The Soviet Union was a state qualified as totalitarian, modeled by a leader who had all the powers, and was interested in achieving the domination of Eastern Europe, including the construction of the Berlin Wall.

The Berlin Wall was built when the western zone began to prosper while the Soviet side suffered economic problems. This, caused millions of Berliners who lived under the communist regime to migrate to West Berlin.

With which the Soviet Union was losing its long-awaited desire for dominion and power.