30 years on from the fall of Berlin video who occupied the eastern portion of Germany ?

The Soviet Union

Explanation:

After World War II, Germany was forced to divide between the Allied forces as a consequence of their military and war crimes. The leaders of the US, UK, and Soviet Union (Harry S. Truman, Winston Churchill, Clement Attlee, and Joseph Stalin) met at the Potsdam Conference to decide the faith of Allied-occupied Germany and establish the order of the post-war world. They divided governance over Germany between the UK, France, the US, and the Soviet Union.

Over time, three parts began to merge, and the part belonging to the Soviet Union stayed separated. Finally, around 1949, the west part of Germany was considered to be under the Allied powers, while the East one was occupied by the Soviet Union. Berlin was on the Soviet ground, but it was also divided between Allies on the west and Soviet power on the east, and separated by the wall.