Nearly every soldier in any war will have directly or indirectly killed an innocent civilian. Which ones are war crimes and which aren’t?
How do you decide and who gives you the authority to do so?
What if the civilian they kill has a substantial effect on the enemy's military capabilities, for example by being someone famous who loudly endorses the honour of signing up to fight for one's country, thereby motivating thousands of young men to do just that?
Once you open the door, where do you draw the line?
[1]: A search for that name mostly brings up links to pages for SS apologia.
Updated link:
Can be used to justify anything.
I think the more baby-steps approach to western cognitive dissonance is to at least get them to be consistent about when it is a good idea to go to war. I'm more than happy to get downvoted pointing out that killing 100s of thousands of Russians and welding them strategically to China was a terrible policy, uniting Asian manufacturing and resource giants is catastrophic for western power. But people were grumpy and didn't want to talk about realpolitik because the Russians are so evil.
Now we have the US attacking Persians in Persia for trying to govern Persia because the US sphere of influence covers the whole world and doing serious damage to the West's access to global oil markets and we have this muted and philosophical response from the powers that be. It isn't just immoral, it is also actively stupid - if we can tolerate this behaviour from the US, why can't we also tolerate Russia on a far smaller and easier to understand scale? How are all the sanctions and weapons deliveries to Ukraine actually justified in the minds of the people making the decisions? It clearly isn't a moral calculation and it seems to be stupid strategy.
If we got some thoughtful and transparent thinkers in power there'd probably just be less wars, they seem to be the fast path to poverty and the upside is hard to spot. There are serious questions about why any of the major conflicts right now looked like a good idea to the people in Washington and wherever NATO is in Europe. Brussels I suppose. Can we try peace and prosperity as a strategy?
Also, the North wasn't democratic either so it was two nondemocratic groups fighting.