I've recently been watching Oliver Stone's Untold History of the United States. While I find the program entertaining and educational, I'm a bit skeptical of some of Stone's conclusions regarding the relationship between the United States and the Soviet Union in the final months of World War II.
In the series, Stone places much of the blame for the degradation of relations between the two super powers on Harry Truman's presidency and hardcore anti-communists within the CIA. He characterizes the Americans as making unreasonable demands on the Soviets regarding the split of influence in post-war Europe and specifically calls out the Truman administration for being unrealistic about Russian national security in regards to the Soviets wanting influence over post-war Poland. Additionally, he characterizes the Soviets as being loyal allies during the war, citing their timely invasion of Japan, which was actually ahead of the date that they promised. He goes on to describe the United States' use of the atomic bomb as a tactic to scare and dominate the Soviets politically, and later blasts Dwight Eisenhower as a brinksman who routinely threatened nuclear war against soviet-backed communist revolutionaries in the post-war proxy fighting, which escalated tensions and pushed the world towards the "mutually-assured destruction" status quo which still exists today.
My question is: Are these characterizations reasonable? Could relations between the United States and Russia have been substantially different if we had taken a less hard-line stance against the Soviets and their communist satellites after World War II? When I look at the world today, I see so much suffering and strife that can be directly linked back to decisions made during the cold war by both sides. But it isn't clear to me if the cold war could have been avoided in the first place. Could it have been? Or were the United States and the Soviet Union destined to be adversaries regardless of how they behaved during the last weeks of the war?
Stone's essential thesis is a very far-left, immediately post-Cold War sort of line, not a new thing at all, the sort of argument that was mildly popular in the late 1980s and early 1990s of a "the US was to blame for the Cold War" vein, what might be called the "revisionist" Cold War argument. In its original conception, it was meant to press back on the "the Soviet Union was to blame for the Cold War" argument that had been commonplace since the 1940s.
I think with hindsight it is easy to see that continual alliance was unlikely to be possible. Stalin was disinclined to trust the United States for a variety of reasons, and even if he did trust them the way he did FDR, it would still have been in his interest to secure as much for himself as possible. It is clear he was interested in doing this in the Eastern Bloc of Europe even before FDR died, to give himself some "space" to avoid a future land invasion.
The Stone/Kuznick thesis is basically that if Wallace had been President, the US would not have used nuclear weapons in the war and would have more or less sought to be a good ally to the USSR. This is highly speculative on every front, but it still doesn't answer the question as to whether the USSR would actually trust the US going forward. I doubt it.
I think one can say that Truman's policies did not help the US-Soviet splitting of interests, and neither did Stalin's, and the combination of the two made for what is reasonably to be considered the Worst of All Possible Worlds Short of Open War. So that is not to say that things could have been better or at least not quite as tense and troubled as they were with both Truman and Stalin. And that is not to say that the US Presidents (Truman, Eisenhower, etc.) did not "fan the flames" or do extremely dangerous things that displayed too little empathy for the Soviet perspective (which was primarily concerned with the very real threats to their security that the US posed, by, say, ringing the USSR with airbases with a large arsenal of nuclear-armed bombers, which the US did by the 1950s). One need not, and should not, take the exact opposite position of Stone; there is a very reasonable middle ground available.
But the idea that there is some kind of perfect, perpetual friendship possible, in the absence of a common enemy, seems quite unlikely to me, and some kind of superpower rivalry, between the world's remaining two major superpowers with diametrically opposed ideologies and attitudes, strikes me as inevitable. Obviously we cannot know for sure.
For what it is worth, the Soviet entry in the Japanese war was more or less exactly on the date they promised at Yalta (three months after ending of European hostilities), and the only reason it was moved "up" from the original date that Stalin had floated (August 10th, from August 15th or so) is they wanted to make sure they were able to grab territory in the Far East before the war ended! I only bring this up to contrast this with the idea that the Soviets were just jumping into the war because they were our good friends — that is definitely and documentably not the case! They did it because they wanted to regain the whole of the island of Sakhalin, and take the Kuril Islands, because the combination of the two would give them easy year-around access to the Pacific Ocean via Vladivostok.