The Cold War, spanning from the late 1940s to the early 1990s, was a defining era in modern history. It shaped international relations, military strategies, and economic policies. The arms race led to the development of nuclear weapons, creating a delicate balance of power and the doctrine of mutually assured destruction (MAD). The clash of ideologies—capitalism versus communism—influenced political movements, proxy wars, and cultural exchanges. Lessons from the Cold War include the importance of diplomacy, the consequences of proxy wars, and the need for vigilance and cooperation. Today, the legacy of the Cold War persists in geopolitical tensions, nuclear threats, and the complex relationship between the USA and Russia.