A "no-brainer" is the notion that a mainland invasion would ever have been necessary at all, with or without the atomic bomb.

It would not have.

When the Russians attacked the Japanese positions in Asia, the Japanese knew the jig was up. The Americans could have stood by, let the Russians devastate the Japanese armies on the mainland (which they certainly would have, having a crushing advantage in tanks and other heavy weaponry over the Japanese), and not lost a man, and the Japanese would have sued for peace anyway within quite a short time.

This, however, would have entailed the Russians possibly greatly expanding their Asian sphere of influence...and THAT Truman was not willing to contemplate. :-)

It was power politics, as always, people. And they called it "saving lives" in order to disguise their more weighty intentions which have to do with the gaining and wielding of power not the saving of lives. It's never about the saving of lives. It's about winning, and winning big.

Pete - Your general description of the Japanese attitude toward negotiations is pretty accurate. In that respect they acted exactly like any other country in their general position usually acts. They did not face up to the real possibility of defeat until it had become really quite undeniable on any rational basis. That's pretty typical, isn't it?

How long do you think the USA would remain defiant, if its navy and air force were smashed and its borders were being threatened with a fullscale foreign invasion? A long time, I figure. No country gives up its own sovereignty on its own land while it still has any means to resist effectively.

But...you don't have to take away another country's entire sovereignty to win or to end a war. You just have to put them in a clearly losing position, as the Japanese did to the Russians in 1905 or America did to Spain in 1898. Then they will negotiate.

(Nice lively thread, isn't it?)