I'm glad you asked, because I think it is important that we re-examine our actions and hold ourselves accountable; your question is part of that. I'm going to provide my subjective opinions; turns out I didn't cast a close vote on this, so my opinions are not strictly responsive to the question, but I hope you'll take them in the spirit in which they are intended.
In my opinion, excellent questions are "trapdoor functions" - When the question is asked, the answer is difficult, but when someone supplies a correct, well researched answer, any reasonable observer can examine the question and answer and agree, "Ahh! so that's the answer, I see it now, and I understand the question and the topic better."
This was a list question - there wasn't an answer, there was a set of answers that could be argued without closure. (and we were well on the way to arguing without closure). In my experience, that is an indicator of an opinion based question.
"War", "Weapon", "end", "long", "cause" - roughly 1/3 of the words in the question were subject to debate, and roughly 1/2 of the important words. That's another indicator that that the result I give won't be accepted by the guy sitting next to me. Excellent questions have answers that when we look at them, we all agree, "yes, that is the answer!". Opinion based questions frequently result in answers that spur yet further argument.
In my personal opinion, if someone had provided a perfect answer, I'm not sure that the Q&A as given would have led me to a deeper understanding of warfare, civilian deaths, danger, history, or anything else.
Closure isn't fatal. Closure is an opportunity to revise a question. In this case, IF this were a question that were important to me, I'd probably rewrite the question taking relevant comments into account, and try again. I think there is an interesting question buried in here, but I haven't the skill to revise it.
Aside: remind me to propose Wallace's corollary to Godwin's law; "Questions that do not terminate with reference to National Socialism degenerate into interminable discussion of terms." If I'm lucky people will argue my definition which will support my point.