Answer: The country that became known as the "Iron Curtain" was the Soviet Union.
Step-by-step explanation:
The term "Iron Curtain" was coined by British Prime Minister Winston Churchill in a speech in 1946, in which he described the division of Europe into two spheres of influence following World War II. The term was used to refer to the political, military, and ideological barrier that separated the Soviet Union and its satellite states in Eastern Europe from the capitalist countries of Western Europe.