I think the rules and procedures regarding bombing have always increased commensurate with the the ability to bomb with precision and to pick out targets.
For example, in WWII - as the long Colhoun quote indicated - the targeting was done by groups of generals with different philosophies of how to follow the rules of war. By the end, a desire to end the war overcame any reluctance on the part of the combatants to do what was possible. Bombing was fairly imprecise anyway. Pilots had to make second-to-second decisions concerning machine guns and bombs while traveling over 300 MPH, and facing enemy fire. WWII was hell on the civilian populations.
By Vietnam, even carpet bombing was much more precise. the bombers were more accurate, for one thing. By the 1960s ground-to-air and air-to-air communication made accurate targeting possible. In WWII a pathfinder would fly in and unload, every other bomber would unload - then everyone flew off. By Vietnam we had forward air controllers (FACs) and lots of communication between the ground troops and the air units.
To be fair, most of this was pioneered in WWII by the Germans and employed with great success by the US Marines in the Pacific, I digress…
Obviously, any raid which ends in women and children being napalmed has to be questioned. As we’ve seen, the military has a disciplinary procedure for this. If it should rise to the level of an intent crime, then the world has procedures. Can-of-worms, ICC, I know…
To finish the story, by Kosovo the targeting has entered the computer age and is done with actual reference to the Geneva Convention, down to the footnotes. Weapons - though prone to malfunction or improper targeting when UN wheat, Chinese embassies, weddings, US troops, or Canadians are nearby - are very precise. he moral questions about war remain, of course.
Fundamentally, the necessary procedure is to train all your officers and troops on the rules of war and the rules of engagement - which should reflect the rules of war. If a lieutenant violates all the established laws, all the planning and programs won’t matter. One argument against the “prisoners in military” idea.