To any pre-WWI mind the outcome of world war II would seem like all world leaders were replaced with absolute fanatics. I think in the 19th century there was a strong idea that civilized nations compromised when disputes arose. On the other side of the debate I think Truman and Stalin both thought that peace could only occur if the entire state apparatus of Germany was dismantled. They assumed that they were reducing the number of wars in the future by permanently ending the existence of Germany.
Hmmm...
Italy surrendered unconditionally in a most reasonable way. Unfortunately they were also occuppied by a bunch of most unreasonable Germans
Germany was ACTIVELY obliterating an entire racial group using industrial methods (and NEVER ran short of troops willing to do the work), with plans to obliterate a second ethnic group as soon as the Jewish situation was resolved. Is that the actions of a civilized state?
Japan was using civilians for bayonet practice, just for the hell of it, across mainland Asia. It worked PoWs to death, along with civilian internees. It conducted bio-weapon experiments on civilian populations in circumstances that would have made Himmler blink. The JAPANESE GOVERNMENT organized formal rape camps where kidnapped women were assaulted time and again, with the only hope for release being a grave after a "customer" went a bit too far. Are those the actions of a civilized state?
The Nazis and Imperial Japanese governments were not civilized states. Overall, their actions would have sickened Attila or Genghis Kahn at their worst moments. Virtually every individual who joined the SS voluntarily or worked with the Einzatgruppen units, even if under orders, were guilty of specific war crimes that carried the Death Penalty. The same is true for every Japanese soldier who handled prisoners (civilian or military) and for most who made use of the "comfort women". That the Allies didn't conduct wholesale executions post-war is one of the great acts of restraint ever undertaken by governments.
To allow them any sort of surrender at all was a remarkable gesture of humanity.