Or the "war crimes" are simply the way they fight.
Sometimes it's impossible to get them to understand our rules of warfare because indeed, they don't make a whole lot of sense. It's like showing up at a construction site and issuing tea spoons because the excavator pollutes too much, is too noisy, uses too much fossil fuels whereas the using tea spoons would require more people therefore create more jobs, is environmentally friendly and causes less trauma to the rabbits that live on site.
It make make a lot of sense to us, giving us this heart warming feeling of "doing the right thing" but for those who grew up with the job, it would seem like utter madness.
Rest in Peace to the fallen.