Why and when did the cold war take place?

The Cold War took place between the years 1945 to 1990. Both of the world's two superpowers of that time period, the US and the USSR, were deeply suspicious of each other and feared that they would become the victim of a global power struggle, therefore they both constantly maneuvered for any available means of improving their strategic position. Due to the fear of nuclear war, the Cold War never became an actual war, but the related conflicts of the period, especially the Korean War and the Vietnam War, were still very destructive. North Korea and South Korea remain hostile to this day, which is in a sense a continuation of the Cold War, which in most other parts of the world ended in 1990. The fact that the US to this day (2012) still does not have diplomatic relations with the island of Cuba is also a lingering aspect of the Cold War.