Calling it "collateral damage" or "manslaughtering civilians" or whatever won't change my argument in the slightest. This isn't a language barrier. Actually, it sounds like the opposite: you're restricting the discussion to people who share your mindset.

Some people feel even stronger than I do and would prefer to avoid being involved in killing even an enemy combatant.

I'm not restricting anything but it's a different discussion entirely.

Discussing 1-how to limit civilian casualties during an otherwise legitimate conflict between two nations is one thing, 2-whether those civilian casualties constitute murder (and 3-by whom) is something else. But through pretty much all of human history, nearly all people have recognized a difference between killing during a war, including innocent civilian deaths, and intentional murder. If you want to discuss #1 you had probably agree on #2 first, don't you think?

I agree it's an interesting discussion, but I really didn't get any of that from the comment you originally replied to. (Please correct me if I'm wrong.) My point was that the word "murder" there is largely irrelevant, the issue is killing in general. For me, there's no definition or level of efficiency that will make me comfortable being able to directly connect my hard work and someone else's death. And trying to frame harm caused by another as blood on my hands due to my refusal to help is ridiculous.

Replace murder with kill. It doesn't change the point. I'm not more complicit through refusing to help them kill in the first place.

Not everyone agrees that a soldier killing a soldier during a conflict is objectively not murder.

Many of us, including many intelligent people, think that all such premeditated killing is objectively murder regardless of the political context.

Please don't handwave this fact away.

Given that some people do not see a soldier killing another solider vs a serial killer killing a random person as different, I think it is relevant. The technical distinction as far as I can tell is homicide (killing in any sense) vs murder (unlawful killing, e.g. not what soldiers typically do). How can one have a discussion about the ethics if those are not different? To flip it around, how could we have a discussion about the ethics of software and human life, if one of us believed that a serial killer killing people was an ok thing to do? e.g. everything would be ok, so there's no discussion? Conversely if all forms of combat killing are not ok, then there's no discussion to be had.

I suspect the idea that “people aren't even honest about what constitutes murder and what doesn't” creates a high barrier to the discussion you’d like to have.

From your post, I think you’re starting from the pov that governments have the right to decide what is murder vs an acceptable killing. Some of the people I’ve met who are most interested in these ideas are staunch pacifists with a strong religious motivation (e.g. Quaker or Methodist) and reject the idea that governments can declare any killing to be acceptable. I don’t believe they’re dishonest, for all that it’s a very different starting point.

Society, not governments, has more-or-less agreed for at least a few thousand years that there is a difference between these two acts. You're free to feel differently but as another commenter pointed out, there's not much of a discussion to be had on the ethics of killing in war if you think any two instances of one human killing another human are identical from a moral or ethical standpoint. Throughout all of human history, most people has believed there is a difference.

Attacking computer security is the only example I can think of for conflict without hurting civilians. Any armed conflict is going to cause additional civilian deaths.

Attacking computers that control critical infrastructure could absolutely cause civilian deaths.