The Cold War is the term given to post-World War 2 relations between the US (and its allies) and the Soviet Union, including states that fell under Soviet influence. It lasted from 1945 to 1991, ending with the fall of the Soviet Union. It is called ‘cold’ because there was no major combat between the chief sides, though various proxy wars took place, for example the Korean War and the Vietnam War.
The main cleavage in the Cold War was between American-style capitalism and Soviet-style communism, with the non-allied movement (including Tito’s Yugoslavia) and so-called Third World countries as players to be won by either side in an ideological and strategic battle for power, influence and resources.
The cultural reach of the Cold War can be seen through American phenomena such as the Red Scare. In the Soviet sphere, democratic or independent movements were sometimes suppressed militarily, as in the case of Hungary, while the US aided nearly any organisation that fought against socialist political movements in places like Latin America and Southeast Asia, including murderous despotic regimes.
The period is generally characterised by a massive nuclear arms build up by both superpowers, which assured ‘mutual destruction’ of both parties should such weapons be used.
The fall of the Berlin Wall in 1989 signalled an end to Soviet Power and the USSR soon dissolved.