It allowed the Axis Powers to continue unchecked.
The dividing line between the Soviets and US/allies.
West Germany was part of the "free" world; EAST Germany was controlled by the Soviets.
It sped things up in Europe; it was really a race between the Soviets (Russians) and the Western Allies, on who could beat whom into Berlin first. The Germans greatly wanted to surrender to the Western Allies, not the Soviets! Had the US/British not reached Berlin when they did, the Soviets (Russians) would have taken over ALL of Berlin, instead of just EAST Berlin.
Soviet Union
In order to defend American interests in the cold war, Reagan streamlined the armed forces and pulled missiles out of Europe. He demanded that the Soviets immediately remove missiles and when they didn't he put American range missiles in Europe and at the USSR.
It allowed the USSR and Nazi Germany to carve up a big part of eastern Europe between themselves, and plunder the region for all they could. But more importantly, it freed up Germany from the threat of a two front war (that is, fighting France and UK in the west, and Russia to the east), which they had unsuccessfully fought in World War I. They could focus their forces on defeating France, which they did in fact do about 9 months later.
Berlin.
The key to winning the war in Europe was the "Russians" (Soviets). The war between the Soviets (Russian Front) and Germany was the primary war in Europe commencing in 1941. In Europe...anything but the Russian Front was a side-show.
The dividing line between the Soviets and US/allies.
Ensuring a balance of power between nationensuring a balance of power between nations
The soviets goal was to spread communism in all of Europe so the soviets needed to get rid of non-communist powers to make this happen.
All of Eastern Europe.
to rein in the soviets and to unite western europe
At the end of WW2.
The soviets had expected to win a quick victory
The Soviets (Russians) had already over-run those positions by wars end. What they had, they kept.
They were afraid of losing control of eastern Europe.