The Cold War phenomenon was prone to collapse due to a number of factors. The first one is economic, when the Soviet socialism was overshadowed by the growing capitalist economies of the United States, Western Europe, and Japan. The Soviet Bloc failed to keep up with the production rates on a global scale.
Soviet Union and the United States were the two superpowers that strategically competed with their nuclear weapons. In the 1970s, the development of the international diplomacy prevented the direct conflict. Yet, according to Anders Stephenson, the Cold War was renewed after Ronald Reagan took office in 1981. Since then, the Soviet Empire started to collapse as well as the Communism ideology across Europe. Even in 1985, when Gorbachev took a strategic shift towards perestroika (restructuring) as well as glasnost (openness), the Soviet system failed to reform. Given the socio-economic collapse, the Soviet Union stared to lose its stance of superpower, and so the Cold War ended once again. That was also preceded by the collapse of communism across Eastern Europe.
To solidify their geo-strategic influence and win comparative advantages in the Cold War, the Soviet government bet on the global card. In 1980, the Soviet Army invaded Afghanistan; in their turn, the United States under the presidency of Jimmy Carter boycotted the 1980 Summer Olympics in Moscow. Further, Ronald Reagan called the Soviet Union as “an evil empire,” emphasized on military readiness, and launched the “Star Wars” as Strategic Defense Initiative (SDI). Since then, the relationship between the two superpowers came to a halt. That way, the Americans won the first-strike capability without being accountable for any consequences thereof. Eventually, economic and military factors caused the collapse of the Soviet Union and subsequently the Cold War era .
Joel, Isaac, and Duncan, Bell. Uncertain Empire: American History and the Idea of the Cold War. Oxford: Oxford University Press, 2012