The "Cold War" is generally considered to be that era from 1945 until 1990, when there were extreme tensions between the USA and the USSR. It was called "cold" because there was never a direct military confrontation: the US Army never fought the Soviet army directly. There were "proxy wars" between nations which were associated with the US and the USSR; in this way, they fought indirectly.
The fall of the Soviet Union in 1989/1990 lead to increased freedom for millions of people in several different nations, but who gets the credit for "winning" the war?
Historians do not agree; a number of different individuals are named as those who "won" the Cold War: President Ronald Reagan; Polish leader Lech Walesa; and Pope John Paul II. Other historians say that not one individual, but movements of people, were the "winners": in East Germany, there were student movements in Leipzig and Dresden which undermined the authority of the communist dictatorship. In Romania, groups met on a regular basis in churches, in direct defiance of communist directives. These groups can be seen as the ones who made the decisive difference.
So it is not clear who "won" the Cold War for the free countries. But, in any case, it remains an interesting phenomenon, because both the USA and the USSR engaged in huge weapon building programs, but these weapons were never used. The fact that hundreds and thousands of very powerful atomic weapons were built but never used demonstrates the power of the concept of "deterrence": by building powerful weapons, one can ensure peace and justice, because no nation would risk the horrifying destruction which would be the result of such an armed confrontation.
In our era, after the Cold War, we live with terrorism; terrorism is conducted by small, quasi-political organizations, not by legitimate nation-states. The tactic of deterrence does not work as well against terrorist organizations as it does against sovereign states.
