During which era was the term "Iron Curtain" notably used to describe the divide in Europe?

The term "Iron Curtain" was notably used during the Cold War, which spanned roughly from the end of World War II in 1945 until the dissolution of the Soviet Union in 1991. This phrase was popularized by British Prime Minister Winston Churchill in a speech in 1946, where he referred to the symbolic division in Europe that separated the Western nations, influenced by democratic values and capitalism, from Eastern nations under Soviet control and communist ideology. This division represented not just a physical barrier but also a stark ideological conflict that defined the geopolitical landscape of the time.

The other eras mentioned do not fit the context of the "Iron Curtain." World War II was primarily characterized by global conflict and military alliances rather than the ideological division that marked the Cold War. The Great Depression, while a crucial period in economic history, was not associated with the specific ideological divides that the term describes. The Renaissance focused on cultural, artistic, and intellectual revival and does not relate to the geopolitical issues of the 20th century. Therefore, the Cold War is the correct context for understanding the significance of the "Iron Curtain."