The rise of nationalism under '' freedom of speech '' soon re-awakened simmering ethnic tensions in various Soviet republics , further discrediting the ideal of a unified Soviet people . One instance occurred in February 1988 , when the government in Nagorno-Karabakh , a predominantly ethnic Armenian region in the Azerbaijan SSR , passed a resolution calling for unification with the Armenian SSR . Violence against local Azerbaijanis was reported on Soviet television , provoking massacres of Armenians in the Azerbaijani city of Sumgait
massacres of Armenians
Sumgait pogrom
History of the Soviet Union (1982–91)