The Cold War ended largely due to a combination of economic, political, and social factors. 1. **Economic factors**: The war was draining Soviet Union's economy as it tried to match up with the West's technological and military advancements while also dealing with internal economic issues. 2. **Political factors**: There was a shift in Soviet leadership with Mikhail Gorbachev taking power in 1985. Gorbachev implemented policies like "glasnost" (openness) and "perestroika" (restructuring), which aimed to bring political and economic reform but ultimately contributed to the weakening of the socialist regime. 3. **Social factors**: People in the Eastern Bloc grew increasingly discontent with their government and began protests and rebellions. Key examples are the unions led by Lech Walesa in Poland. A notable event marking the end was the fall of the Berlin Wall in 1989, which symbolized the collapse of communism in Europe. Finally, in 1991, the USSR officially dissolved when Boris Yeltsin took power in Russia and various other regions declared independence. This question would however be better suited for a history-related Q&A site.