See Anatoliy Golitsyn's book New Lies For Old (1984).
He was a KGB colonel that defected to the U.S. in the 1960's. He went to the U.S. state department with what he knew about the Soviet's long range plans. They wouldn't listen, so he asked to be allowed to put it in a book, and he did, in 1984.
In his book he predicted that if it was time for the Soviet's third final phase of their long range strategy against the West, then they might allow the Berlin Wall to come down.
He stated the long range plan is for a one socialist Europe, from the Atlantic to the Urals, and the joining of East and West. (this has been the movement of the U.N. controls over education, finance, military, and international politics for several decades).