Main reasons:
1) Historical reasons:
After the Eastern European countries came to power, they all copied the Soviet model and were largely controlled by the Soviet Union. The Soviet Union forced the eastern European countries to be consistent with it in their domestic and foreign policies. In fact, Eastern European countries have no independent rights. Historically, the Soviet Union and Poland, Romania and other countries have national grievances, such as the Katyn incident. The ethnic relations between the Soviet Union and eastern European countries have been tense for a long time.
2) Religious reasons:
The Catholic forces in some eastern European countries have a long-term historical influence and a deep mass base, while the rigid religious policies in eastern European countries have aggravated social contradictions.
3) Internal reasons:
Economically, most countries have developed slowly, the reform has not achieved much, and the gap with western European countries has widened. Economic difficulties lead to economic crisis and induce political crisis and ethnic contradictions. Politically, due to the serious destruction of democracy and legal system, the political parties and governments in eastern European countries are divorced from the masses. The decline in the quality of party member and the Party's cadres is an important cause of dissatisfaction and drastic changes.
4) Soviet factor:
Gorbachev's reform loosened the eastern European countries, and his program of building "humane and democratic socialism" and "new thinking" in foreign policy led to ideological confusion within political parties in various countries and promoted the reorganization, differentiation and transformation of political parties in eastern Europe.
5) Western factors:
Western countries lured Eastern European countries through various means such as loans, trade, technology and ideological infiltration, and urged them to move closer to the West.
6) Economic factors:
Beginning with the 1936 Constitution, the Soviet Union began to establish a highly centralized planned economic system "Soviet model". The disadvantages of this system have led to the great reduction of economic vitality and rigid administrative system in the Soviet Union and Eastern European countries.
Introduction: Drastic changes in Eastern Europe (also known as drastic changes in the Soviet Union and Eastern Europe and democratization in Eastern Europe, and also known as Eastern Europe 1989 series revolutions in western society). From the end of 1980s to the beginning of 1990s, the political and economic systems of various socialist countries in Eastern Europe have undergone fundamental changes, which means that the Stalin-style socialist system eventually evolved into the violent turmoil of the capitalist systems in Western Europe and the United States. Drastic changes began after 1989. It first appeared in Poland, and later extended to East Germany, Czechoslovakia, Hungary, Bulgaria, Romania and other former Warsaw Pact countries. This event ended with the disintegration of the Soviet Union, which is generally considered to mark the end of the Cold War. Except for the bloodshed in Romania, events in other countries ended peacefully in free elections, and Albania was the last country in all eastern European countries to end the ruling of the * * * production party.