The idea is to make it easy for your enemy to surrender. If they know their fate is most likely death if taken prisoner, that only stiffens their will to fight. The Nazis found that out the hard way in Russia. If they treated the Ukrainians and Russians better, the Red Army would have capitulated.
Exactly. Good point. If the now enemy values its own life.
The ongoing conventional war with Japan would have been horrible. Probably the worst in all of humanity. But the Japanese people were willing to fight to the death. Every last person. Dropping the bomb was unfortunate but necessary because the end result was surrender it actually saved lives. It was horrible all the way around. But necessary.
Sadly, there will never be peace for Israel. It is a religious war with a totalitarian theocracy. And in the end, Israel will be destroyed... almost.