Dr. Szliard's (sp?) feelings not withstanding, the concept that a "demonstration bomb" would have been effective is laughable.
The Japanese had had repeated demonstrations that the United States was more than willing to destroy entire cities. The only difference was that prior to August 6 it had taken several hundred planes to do so.
A "demonstration" a few hundred, or thousand, miles from Japan wouldn't have made any sort of effective impact on the Japanese given their military mindset.
Again, it should be noted that significant elements of the Japanese military resisted surrendering even AFTER the dropping of two atomic bombs.
Slizard never understood the Japanese mentality. Few did understand the Japanese mentality during WW II. Few understood the concept of willingness, even desire, to die for one's Emperor as opposed to going home to family and friends alive.
The only people who had even an inkling of what the Japanese mentality truly was were those who were fighting the Japanese.
Slizard knew about the scientific prospects and capabilities of the bomb.
That does not, however, make him an expert diplomat, or even an expert in its application.
That's like saying that the engineer who designed the tires used on Indy race cars is, in fact, a qualified Indy driver. Nothing could be farther from the truth.
As for Japan's surrender, the Japanese had put out peace feelers, but were NOT engaged in "surrender negotiations" with the Soviets. The Japanese and Soviets were still under the auspices of a non-agression treaty when the United States dropped the first atomic bomb on August 6. The Soviets only entered the war later.
But once again, as agreed to by the allied powers -- the United States, Great Britain, and China (the major combatants in the Pacific), the ONLY acceptable Japanese surrender would be immediate and UNCONDITIONAL.
The "feelers" that Japan put out were hardly unconditional, and as such were unacceptable to the United States or its allies.
Of course, we then have Szliard asking "why did we have to have an unconditional surrender."
Because that's what the Allies demanded. Nothing short of that.
Szliard once again attempts to use his position of authority as a scientist to cast himself in the mold of a diplomat and warrior. Sorry, it simply doesn't work that way.
He could just as well ask "why was it necessary for the United States to respond to the Japanese attack on Pearl Harbor with a declaration of war? Couldn't we have just taken the lump and ultimately ignored it?"
You are correct in one thing, St. John. There was some aspect of demonstration for the Soviet Union in all of this, but it was primarily about forcing the unconditional surrender of the Japanese.
The terms that we later GAVE to them are unimportant.
The important part was Japanese ACCEPTANCE of the unconditional nature of their surrender.