How did the origins of the Cold War reflect different American and Soviet traditions?
In this answer, I am going to use "traditions" to mean set ways of thinking that were typical of these two countries.
The Cold War started because of Russia's "traditional" suspicion and fear of the West and because of America's "traditional" belief that people should be able to decide major political questions for themselves. Because of the French invasion of Russia in the 1810s and the German invasion in WWII, among other things, Russians had long been fearful of attacks from the West. Because of this, they tried to create a buffer zone of satellite countries in Eastern Europe. This reaction to their "traditions" did not mesh well with US "traditions." US traditions held that telling other countries (at least other countries populated by Europeans) what their system of government would be was simply wrong.
In this way, Russian traditions demanded a protective zone and American traditions caused the US to perceive Russian actions as wrong and offensive.