Why might Churchill use iron curtain to refer to the division between western and Eastern Europe?

Churchill used the term "iron curtain" to symbolize the ideological and physical division between Western democracies and Eastern communist nations after World War II. This phrase vividly captured the stark contrast between the freedoms enjoyed in the West and the repression in the East, emphasizing the need for vigilance against the spread of Soviet influence. By using such a powerful metaphor, Churchill aimed to rally the West to recognize the seriousness of the geopolitical divide and the need for a united front against totalitarianism.