Final answer:
The USSR's buffer zone in Eastern Europe after World War II was known as the Iron Curtain.
Step-by-step explanation:
The "buffer zone" that the USSR created in Eastern Europe after World War II was nicknamed by Winston Churchill as the Iron Curtain. This term was used to describe the ideological and physical division between the Soviet-dominated Eastern Bloc countries and the Western democracies. The Iron Curtain represented the Soviet Union's control over the countries in Eastern Europe and their exclusion from the Western sphere of influence.
Learn more about The Iron Curtain in Eastern Europe after World War II