To what degree was the “Iron Curtain” both a cause and reflection of different evaluations of the present, opposing views of the future, and powerful, contrasting memories and “lessons” from the past?
The Soviets clearly believed that one lesson of World War II was that they should never again allow their western flank to be as vulnerable as it had been in 1939. At the same time, the people running the Soviet Union also wished to impose communism on as many people as possible, so that there were both ideological as well as highly practical reasons for them to impose an "iron curtain" on Eastern Europe. They were probably also aware that their system would be far less attractive to their own people if western-style democracies existed right on the borders of the Soviet Union.
As George Kennan argued, Soviet conduct was to a great extent influenced by the past, and that past had seen the Soviet (Russian) western frontier invaded repeatedly by Germany with great destruction and loss of life. The desire to build a ring of satellite states, as well as US determination not to allow Western European governments to be overtaken by communists, and even to expad their influence into Turkey and elsewhere in the so-called Russian sphere of influence, resulted in the construction of what Churchill called an iron curtain. But the creation of these boundaries, not just in Europe but in places like Korea, was also understood as a way of keeping the peace, as long as both sides, at least tacitly, recognized them.
It was a combination of all of these things. The Russians and the the West had different views of the lessons of the past. The Russians, for example, thought the past taught them they needed a buffer between them and the West. Going forward, the two sides thought that the world should develop differently. Both of these kinds of things led to the creation of the Iron Curtain.