the Iron Curtain
noun [ S ] uk/ˌaɪən ˈkɜː.tən/ us/ˌaɪrn ˈkɝː.t̬ən/
铁幕(指原东欧共产主义国家与欧洲其他国家之间的分界线)
From 1946-1989, the Iron Curtain was the name of the border between Western Europe and the communist countries of Eastern Europe. The Iron Curtain made it very difficult to travel into or out of Eastern Europe.