One of the few things that could penetrate the “iron curtain” were ideas conveyed on radio waves. “The Voice of America” network broadcast to the peoples of the Soviet bloc, so that they were never completely isolated, and hearing only what the Communist dictatorships wanted them to hear.
Ironically, despite the victory of democracy over dictatorship that brought the Cold War to an end, within American society there has slowly but steadily developed in too many of our own colleges and universities a set of restrictions on what can be said on campus, either by students or professors, or by outside speakers with views that contradict the political correctness of our time.
There is no barbed wire around our campuses, nor armed guards keeping unwelcome ideas out. So there is no “iron curtain.” But there is a curtain, and it has its effect.