A significant economic impact at the time was the removal of of agricultural land and of forest from production. While much of this has been returned to use, agricultural production costs have risen due to the need for special cultivation techniques, fertilizers and additives. Politically, the accident gave great significance to the new Soviet policy of glasnost, and helped forge closer Soviet–US relations at the end of the Cold War, through bioscientific cooperation. The disaster also became a key factor in the dissolution of the Soviet Union in 1991, and a major influence in shaping the new Eastern Europe.