In the mid-1960s, Czechoslovakia was part of the Warsaw Treaty Organization (also known as the Warsaw Pact). That is, the country was part of the Eastern Bloc, behind the Iron Curtain. Czechoslovakia was a communist country essentially controlled by the Soviet Union. The political regime that was in power in Czechoslovakia was somewhat repressive, though the situation would grow worse in 1968. To understand the situation in 1965, the country's history during and after World War II.

Just prior to and during World War II, the country was split apart by Nazi Germany. Slovakian nationalism became strong, as it would again in the mid-1990s, and Czechoslovakia was torn apart. For their part, independent Czech patriots were put in concentration camps. During the war, Czechs suffered greatly. After World War II ended, Czechoslovakia was liberated by the Soviet Union. Though many in Czechoslovakia called for American intervention...