Militaries have a lot of experience, and an exceptionally poor track record.

I don’t remember the last war that didn’t have credible evidence of war crimes occurring. Were bombing civilian infrastructure in Iran, Iraq had Abu Ghraib among all the Collateral Damage stuff, the Highway of Death in the Gulf was probably a war crime, Vietnam had My Lai, WWII was the advent of carpet bombing civilian infrastructure. I can’t think of any for Korea, but I also know very little so that doesn’t say much.

We still haven’t charged anyone for the second strike on that fishing boat in South America, and I haven’t heard a single rationale for why that’s not a war crime other than “fog of war”.

The US doesn’t even really have a meaningful system for finding and prosecuting these, because we aren’t signatories for the ICC and have a bill saying we’ll invade if they charge one of our service members with a war crime. We aren’t basically the furthest thing from having any experience prosecuting war crimes. I can probably count on my fingers the number of cases we’ve tried. We rarely charge our own service members, and we usually kill foreign combatants rather than capture and charge them.

A poor track record compared to who? The Romans?

War includes death by design. The trajectory is trending toward less unjustified death.