From a misguided Jewish pundit: I want to be really clear about this to anyone reading or sharing this: There are no "basics of morality in wartime." There is morality, period. If your morals change when you go to war, you were always a sociopath unsuited to the task. This is trash.
----------
The reason there is a distinct discipline of “just war theory” or “laws of war” or “morality in wartime”—is because in war, we take up the most powerful weapons available to us and use them to try to annihilate or cripple vast formations of heavily armed men and put an end to them as an effective destructive force.
This activity involves actions that resemble almost nothing we encounter in civilian life. For example, it can be perfectly moral in wartime to kill or assault a man you’ve never met before, or to take him prisoner and intern him for years, for no reason other than that he is wearing the uniform of an army that you seek to destroy.
The matter is a little more complex than that, but I think anyone can understand the basic point: In civilian life, we are not permitted to initiate violent acts against others because of the clothes they decided to put on that morning.
Similarly, in war it can be permissible to destroy a factory or railway line or an airport or a dock because it is being used to supply and feed an army that you seek to destroy. And this basically without reference to the question of who owns it.
But in civilian life, we are not permitted to destroy the property of others, simply because it is being used to supply food or clothing or implements of destruction to third parties of whom we disapprove.
Everyone who has spent the least effort in studying the laws and morals of warfare knows these things and can easily name additional examples.
This does not mean that anyone’s “morals change” when they go to war. It means that the situation in which we find ourselves is radically changed, and that laws and morals that must regulate our behavior in this changed situation are very different from those of a society at peace.
I object to your using words like “sociopath” and “trash” when addressing me. I haven’t done anything here other than to take a familiar position on well-known subject. It is true that many people on this platform are uninformed, and maybe you’re one of them. But that’s no excuse for your misbehavior.
---------
Please listen to our Hilchos Melachim Umilchamoseyhem shiurim for more on the topic of morality at war.