Why did a cold war exist?

-the soviets wanted more control in germany.
-an ideological war existed.
-the western countries were against the eastern countries in an imperialist race.
-to stop future wars in europe.

The Cold War existed as a response of the Western capitalist countries of Europe and the US and Canada to the threat they considered the Soviet Union posed to their economic and political interests both in Europe and also throughout the world. They felt this threat from the Eastern European countries that were invaded by the Soviet Union in their drive to defeat Hitler. After the war many of these countries like Romania, Czechoslovakia etc had socialist governments like the Soviet Union and were considered part of the Soviet sphere of influence. Eastern and Western Germany divided by the Berlin Wall were symbolic of this division. After the WWII and also the death of Stalin, there was major contention between what came to be known as the two world superpowers, the US and the Soviet Union and there was a near nuclear war over for example the US stopping the installation of missiles in Cuba in the early '60's. 

If i remember correctly it was caused by people hurling bodies at a country for some reason and them they all became infected