Alex WellersteinVerified account

What this meant in practice was that the Japanese were trying, through two separate avenues, to court the still-neutral USSR, with the hope that they could act as an intermediary between the US and Japan in negotiating such an end to the war.

What would that look like? We don't really know, because the USSR never gave the Japanese an audience, because they were already committed to joining the war against them, in exchange for territory. But we'll come to that in a moment.

The core component of what the "peace" faction of the Japanese high command definitely wanted was a preservation of the Emperor system, and guarantees that the Emperor wouldn't be tried as a war criminal.

When I explain this to US audiences, I emphasize that this is kind of like insisting that the US be able to retain its Constitution: it's foundational to the concept of the nation. It was seen as absolutely core to Japanese identity, history, and nationhood; i.e., non-negotiable.

Separate from that, they floated a few other ideas of things they might get to "keep," such as foreign territories and the like. So again, we don't really know what they wanted. It wasn't as simple as an easy guarantee of the Emperor's safety, but that was the core piece.

The US, it is worth emphasizing, knew about these efforts and these concerns. They had cracked Japanese diplomatic codes well before. They incorporated discussions between the head of the foreign minister and the Japanese ambassador to the USSR into their strategy.

This is important when considering the US choices of July 1945, esp. at the Potsdam Conference. Truman was lobbied by both the Department of War and Churchill to give some guarantee as to the Emperor's safety in the Potsdam Declaration, as they saw that this was a sticking point.

Truman, following the advise instead of his Secretary of State, James Byrnes, deliberately decided not to do this. It isn't entirely clear why, but the fact that by then he felt that Japan was likely to surrender without an invasion anyway played into it.