I would agree that both the Soviet Union and the United States need to share responsibility for the Cold War. Looking back through history you can find examples from both sides that contributed to the continuation of the Cold War over the years.
Another way to look at this is that, instead of assigning blame to one side or the other, we can view it as a historical inevitability. There were six empires during World War II: Japan, Germany, Britain, France, the US, and the Soviet Union. To a lesser degree, I suppose you could include Italy.
By the end of the war, Japan, Germany and Italy had been destroyed, conquered and occupied. France was struggling to recover from 5 years of occupation by Nazi Germany, and was near the end of their imperial era, while Great Britain, even though they were on the "winning" side, was broke.
That left the Soviet Union and the US to compete on the world stage and, coincidentally or not, these two nations also had opposite and competing ideologies as well.
I don't necessarily think we can blame any one country in this scenario. Certainly, both the "West" and the "East" have to be culpable to a certain extent, though who must bear most blame is probably going to be the result of an inquiry for someone's PhD thesis. Both the USSR and the USA helped escalate the conflict at various stages.
I think the United States has to take some of, if not all the blame in this scenario. Our need to maintain our power and our sense of ethnocentricity after WWII meant we were never to going to leave the Soviet Union alone. In addition is it the rise of nuclear weapons (which WE used in WWII) that led to the more serious nature of the cold war, always threatening to make it a "hot" one.
Pohnpei makes a good point in the previous post. Although the United States and the Soviet Union were obviously the two main culprits, it was the Germans who created the Soviet mistrust of Western Europe and its allies.
I'll blame it on Germany. That may sound like a joke, but it's not meant that way.
The Soviets took Eastern Europe because they feared being invaded from the west. Germany had just done this too them early in WWII. The German invasion (along with that of Napoleon way back in the 1810s) made the Soviets really afraid of the West.
Because they feared the West, they took Eastern Europe. Because they did that, the US feared them and the Cold War was on. So, in a way, it was the German invasion of the Soviet Union in 1941 that could be blamed for the Cold War.
Blame could probably be shared equally between the United States and the Soviet Union. Primary responsibility would be with the Soviets, who refused to withdraw from Eastern Europe, and planned to continue their expansion. Winston Churchill warned that "an iron curtain" had followed over Eastern Europe. In the United States, there was a second Red Scare, and the belief that the Soviets would attempt to take over here; primarily through subversion. Propaganda ran high on both sides. When the Soviets developed an Atomic Bomb, the United States went one step further and developed the Hydrogen Bomb, which the Soviets quickly duplicated. President Truman's policy of Containment--that is to prevent communism from spreading beyond the areas which it then occupied--was also a factor in the escalating tension. In the end, the entire world was separated into the two camps, East and West. Chances are it would not have happened had the Soviets not been so aggressive; yet the propaganda in the U.S. was also a substantial factor.
The USSR was communist and we did not want to be but USSR wanted to take over and make US communist so was that not the fault of the USSR?
All those who took part in it...