Oliver Stone frequently says 'the Japanese wanted to surrender towards the end of WW2, we didn't want them to so we could have an excuse to use the Atom bomb to scare the Soviets', is this true?

I recently posted this on another subreddit, but it applies here:

Key members of the Japanese high command (including the foreign minister and Hirohito) were sending out peace feelers to the USSR, with the hope that they would negotiate something with the other Allies that was less than "unconditional surrender." We don't know what the terms would have been since they never got a chance to offer them (because the Soviets, having already committed to war with the Japanese and the spoils it would get them, gave them the run-around). Some of the indications from the MAGIC intercepts (which Truman et al. were aware of) indicate they had somewhat fanciful notions of their bargaining power, some of them indicate that the main sticking point was a lack of certainty about the postwar role of the Emperor (which Byrnes and Truman purposefully declined to clarify in the Potsdam Declaration, even at the encouragement of Stimson and Churchill).

So there is some half-truth in this, though to call it a pure "suing for peace" is misleading. Some of the high command were trying to play a diplomatic game because they saw that only military ruin was in their future. Some were not — the militaristic ones in the high command hoped that spilling enough blood would lead to a relaxation of surrender terms or some kind of magical reversal of fortunes. The US was aware of the "peace" overtures, as were the Soviets, and both purposefully conspired against any negotiated peace (for different reasons).

I only point this out because I fear that the common, "traditionalist" response is just as bad history as the extreme "revisionist" version. The truth is much more in the middle.

-- A good source for this is Hasegawa's Racing the Enemy.

The "we just wanted to use the bomb to scare the Soviets" — most historians today don't think this thesis (known as the Alperovitz thesis) has much weight to it. There were some in the Truman admin who saw this as a "bonus" to using the bomb (Byrnes seems to have been aware of it) but it doesn't seem to have been anyone's primary motivation.

Why'd they use the bomb? Because they had the bomb to use. Because they wanted unconditional surrender. They were going to use every weapon at their disposal. The plan was to use the atomic bombs, then do more firebombing, then invade. That the Japanese surrendered before then makes it look like the atomic bombs were really planned as a "finishing" maneuver, but nobody knew whether they would really make the difference and were not counting on it.

A more interesting question is why'd they use the bomb when they did? That is, what's up with the timing of the bomb? Here is where the diplomatic machinations come into play: Truman said that the atomic bomb could be used as soon as possible any day after August 2nd, when the Potsdam conference ended. Why? He wanted the bomb to be used before the Soviet entrance into the war, which as far as he knew was planned for mid-August. The one real hope for the bomb was that it would end the war before the Soviets entered it, thus depriving them of any spoils in the East. In the end, it didn't do that, because the Soviets got their act together to declare war in between Hiroshima and Nagasaki.