1. In the entire war, not one single Japanese officer had surrendered the troops under his command. Surrender was not and never would have been an option. Furthermore, the home island was no more outmanned that Iwo Jima. How many Japanese surrendered there?
2. We had broken their code, and were listening to them. No Japanese official was discussing surrender, despite whatever fairy tale you have bought into. And, finally, Sherman deliberately avoided military targets and attacked civilians. Give me an example of one MILITARY target that he attacked.
Easy arguments to counter;
1. While no Japanese officer of note ever surrendered his troops, starving, ill-equipped Japanese troops with inadequate weapons may have stayed in their foxholes to die valiant deaths,their defeat was a foregone conclusion. If you measure war simplitically in terms of how many of the enemy you kill, you would be inclined (as you are) to build the Japanese of 1945 up into a major power.
I remind you that at the time of surrender, 2/3 of the Japanese army was still in the field,totally unengaged by any Allied force of consequence and cut off from the Home Islands, unable ot come to their defense, and incapable of offensive action. You cannot fight wars defensively, so the Japanese were done. Through and through.
Starvation was an even more critical factor. It was known (form the same code intercepts that you cite) that Japanese food shortages were crippling the country. SO were shortages of critical materials (iron ore, brass, oil, bauxite, aluminum, etc, etc). The capacity to continue to feed the population, supply the military, and continue war production were approachiing nil. Once the ready-to-hand stockpiles of materials were used up, Japan would be defenseless. The question in this reagrd was how long the US Navy (which had Japan completey bloackaded) could continue out against the Kamikazes, while waiting for the Japanese to finally run out of the means to continue fighting.
2. No fewer than THREE Japanese surrender offers were tendered from May to July, 1945. One through Moscow (which never passed it on), one through Switzerland and another through Sweden (and the Magic intercepts show all of these, in minute detail, as well). The reason why they were not entertained (or entertained seriously in the case of the negotiations in Bern with Allen Dulles) was because the terms under which these surrenders would be effected would make a shambles of the united Allied front and the concept of "Unconditional Surrender".
If anyone was really interested in ending the war free of political constraints (that is, just for the sake of ending the conflict), a Japanese surrender was possible months before Hiroshima.
Going back to Sherman, if you don't consider rail lines and hubs, ports, bridges, shipyards, armories, farms and factories to be legitimate military targets, then I'd be interested in just you think are legitimate military targets. The point is that while Sherman inflicted devestation, there was no policy of deliberately killing civilians in order to "degrade the enemy's war effort" or "break his morale".