A book I'm reading brought this to mind. During the Nomanhan Incident, the Sovs had a number of TB-3 heavy bombers available. While not the most modern of aircraft, what do you think the extended outcome might have been, had they used the TB-3s to fly a night mission loaded with incendiaries, to bomb Tokyo? The had the range, 1240 miles for almost a round trip from Vladisvostok to Tokyo, and most of the way back. A blow from Stalin, and try to recover the crews in the Sea of Japan, almost home. Not beyond the Russian mind set at the time. Alternatively, the TB-3's could have hit almost any norther city and made it back to a Russian base. At the time, Japan had next to no night defenses, and I think the situation would have been chaotic in the extreme for the Japanese. Their homeland violated very early on, tough resolve shown by the Sovs. Might it have had any influence on their thinking before Pearl Harbor, knowing the US and USSR would have become allies?