When did the Cold War begin?

Recent discussion in my European Diplomatic History class with Professor Sweeney has prompted me to reconsider what I have long believed about the origins of the cold war. In my research leading up to our Paris Peace talks exercise, I was reading about French strategies ragarding the Balkan states following World War I and the Russian Revolution. The basic French strategy was termed a “cordon sanitare”; a string of small but strong Eastern European nations (Greece, Romania, Serbia/Yugoslavia, Czechoslovakia etc) that could both replace the former Russian alliance against Germany (the role of maintaining the second front in a war) as well as form a buffer against the Russians themselves. The Bolsheviks were thought to be dangerous by the majority of Western powers, particularly France and Britain. I stumbled across French author Andre Fontaine’s assertion that it was in fact this French fear of the Bolsheviks that was the very beginnings of the Cold War. Coupled with the western intervention in the Russian civil war, the cordon sanitaire forms an interesting argument for the fact that the Cold War predates World War II. I find it hard to agree with this argument as it gives a great deal of credit to France and England for their foresight, and it might be seen to suggest that the Cold War was inevitable once the Bolsheviks had gained power. It does however bring up this point of exactly when the Cold War began. Common wisdom says it began sometime in 1947. According to Encyclopedia Brittanica, it was first used as a term in the U.S. in 1947 by Bernard Baruch. However, one can see the rivalry between the U.S. and Russia dating back to the summit meetings between the Allies during World War 2. In David Reynolds book Summits he talks about the Yalta conference as being a precursor of what is to come. Even though Yalta is the only WWII conference included in the book, Reynolds hints that similar signs of the post-war rivalry could be seen in the other conferences. Reynolds and Fontaine both look at the appeasement of Stalin by Roosevelt and Churchill as being a factor in Stalin’s ambition after the war. As an aside, Summits was very interesting, both as a wide lens view of 20th century history, and in its component parts dealing with individual meetings. But I digress. This then is the question, when did the Cold War start? And how much can be reconsidered? Personally, after having seen small parts of 2 ideas that differ from the traditional understanding, I would agree with Reynolds that the Cold War had its earliest beginnings in the meetings near the end of World War II, including Potsdam and Yalta. The other thing I think this speaks to is just how is the “Cold War” defined? Was it just the nuclear age rivalry between the USSR and the USA? Was it between Warsaw pact nations and Nato? Communism and Capitalism/democracy? Or Russian Bolshevism vs. the traditional western allies? I would imagine we will get to discuss all this later in 358 when Prof. Sweeney gets to the post-WW2/Cold War era.