The Sinatra Doctrine was a Soviet foreign policy under Mikhail Gorbachev for allowing member states of the Warsaw Pact to determine their own domestic affairs.
When asked whether this would include Moscow accepting the rejection of communist parties in the Soviet bloc, he replied: "That's for sure … political structures must be decided by the people who live there."
From the Pan-European Picnic in August, it was clear to the media-informed Eastern European population that, on the one hand, the Soviet Union would not prevent the opening of the border.
[2][3] These developments greatly disturbed hardline communists such as the East German leader Erich Honecker, who condemned the end of the Soviet bloc's traditional "socialist unity" and appealed to Moscow to rein in the Hungarians.
In a few months, the communist governments of East Germany, Czechoslovakia, Bulgaria, and Romania had all been overthrown, thus bringing the Cold War to an end.