In 1971, the Warsaw pact countries proposed a conference with NATO to discuss European Security. The conference began in Helsinki in 1973 with thirty three countries attending. A series of meeting followed over the successive months with an agreement reached in 1975. This agreement covered three 'baskets'
This contained an acceptance that the borders of European countries were 'inviolable'; they could not be altered by force.
This promoted links and exchanges across the Iron curtain in the areas of trade and technology.
This included an agreement to respect human rights such as freedom of speech and freedom of movement across Europe. The West saw the acceptance of these issues by the communist states of Eastern Europe as a significant step forward. In reality, the Soviet bloc governments ignored or paid lip service to the human rights agreement.