The army, political, and ideological buffer established involving the Soviet bloc and western Europe from 1945 to 1990.
A barrier that stops no-cost change of tips and information: "That division and also the editorial division are divided by an almost impenetrable iron curtain” ( Brendan Gill).
A barrier made of iron in the theatre, lowered between your stage together with auditorium for safety or even avoid interaction.
Any impenetrable buffer.
an impenetrable buffer to communication or information especially as enforced by rigid censorship and privacy; employed by Winston Churchill in 1946 to describe the demarcation between democratic and communist nations