Which of the following countries was considered to be behind the Iron Curtain post-WWII?

The country considered to be behind the Iron Curtain post-World War II is Poland. Following the war, a division of Europe emerged, with Western countries aligned with the United States and Eastern European countries, including Poland, aligning with the Soviet Union. This division was symbolized by the Iron Curtain, which represented the ideological and physical boundary separating communist nations from democratic ones.

Poland, as part of the Eastern Bloc, fell under the influence of the Soviet Union and experienced a significant reduction in political freedoms and an increase in Soviet-style governance during this period. The term "Iron Curtain" was famously used by Winston Churchill to describe this divide, and Poland's alignment with the Eastern powers during the Cold War solidified its status as a country behind the Iron Curtain. Other countries listed, such as Belgium, Austria, and Greece, were not part of this Eastern Bloc alliance and therefore did not fall behind the Iron Curtain. Belgium and Greece were aligned with the West, while Austria had a complex status but was not controlled in the same manner as Poland.