Complex sentence: It was not even staged in a socialist state until November 1968 when it was shown in Prague after the invasion of Czechoslovakia by fellow Warsaw Pact forces; appropriate given that differences in Communist doctrine is one of its themes.
Split into simpler sentences: It was not even staged in a socialist state until November 1968 when it was shown in Prague after the invasion of Czechoslovakia by fellow Warsaw Pact forces. This was appropriate given that differences in Communist doctrine is one of its themes.