In most of the East European countries single party communist rule was established. But with the rise of nationalism people started to assert their democratic rights.
Soviet empire got another shock when East Germany was merged with West Germany. It was seen as a defeat of communism.
There was a split in the Soviet Communist Party in 1989.
The emphasis on heavy industry and armament made Russia powerful but failed to meet the expectations of the people in terms of food production and consumer goods.
As all factors of production-land, property and factories were owned by the state so it killed people’s incentive to work.
In 1980s state treasury was empty and people had to agitate to get their salaries.
The reforms started by Mikhail Gorbachev were not radical enough to revive the economy instead it created more problems.
The censoring of the books, plays, music, literature had shocked the creative writers.
Revolution in informational technology had enabled the soviets to know, hear, and see what is happening outside in the world.
People could now compare their political system with that of the system in the west.
There was large scale discontent and this discontent was transmitted to the masses by intelligentsia.
Russia was spending large amount of national income in manufacturing weapons than promoting welfare among the masses.
Russia always wanted that the eastern Europeon countries should continue to toe the Soviet Line in everything they did. The policy of interference in the internal affairs was not liked by many countries.
The rise of nationalism and demand for complete autonomy by the Republics became the final and the most immediate cause for the disintegration of Soviet Union. By November 1991 thirteen out of the fifteen republics had declared their independence. The disintegration of the Soviet Union gave birth to a new World Order. The bipolar world was replaced by a Unipolar world led by United States.