Asking someone what they think they did wrong is the oldest trick in the conversational book when the speaker isn't sure what, in fact, the other person did wrong. It won't work here for obvious reasons but it's probably a stock phrase without any thought behind it. Oh well, this is the non-specialist team that's not specced for aliens.
"I've second-guessed myself about many things, and regretted some decisions. The reason for that is that they didn't accomplish my goals or conform perfectly to the army's laws. Our goal here is to understand how I would have behaved if I had had different goals or had been operating under a different set of rules, namely those for not being evil-according-to-Pharasma. If I understand correctly, that means things I already regret aren't indicative of anything."
"I'm not sure what's relevant to the overview. As I said, I volunteered for service, and if war is generally or often evil then I might have used the years before age eighteen to find a legal way to avoid conscription. I could certainly have refused command positions and decision-making authority."
"I have served as an aerial mage, a commander of a regiment of such mages, a trainer in two different settings, and eventually a commander of a larger combined-arms unit including infantry and artillery with the attendant logistics, and I worked directly with staff officers as well as field commanders. I've fought in five different war theaters against four enemy nations, and led several highly specialized missions. I don't know what is relevant; I'll start by going over the most obvious situations when noncombatants are involved. ...I should clarify that, by our laws of warfare, noncombatants can be valid military targets, most obviously army supply trains and military manufacturing facilities but ultimately any installation that is materially aiding the enemy's war effort, even if it also or originally serves a valid civilian purpose and even if enemy civilians are harmed in the process."
"For example, we can destroy bridges and railyards in the enemy's rear and they can't stop us from doing it by keeping a civilian permanently on the bridge, because if that were allowed then everyone would put token civilians everywhere and - maybe that would be good, if it worked, but you can extend that principle to avoiding war altogether and yet here we are. More realistically, if we raid an enemy city and blow up an ammunition factory, some number of civilians working in it will die in the explosion and civilians on the surrounding streets and buildings might also die in the resulting fire. It's very hard to get good estimates of such civilian casualties since every country naturally wants to minimize the numbers it reports or to suppress the news altogether, both to limit enemy intelligence and for internal propaganda."
"Even in combat with enemy forces, there is no good way to verify that there aren't noncombatants involved. If you see who you're shooting at you can avoid people out of uniform and protected personnel like medics, but aerial mages and aircraft and artillery can all operate against ground targets miles away and often can't see much beyond that the target is an enemy camp or unit. Artillery in particular prefers to stay out of direct sight and use indirect fire, targeting coordinates relayed by coordinators who rely on aerial mage spotters which are typically from a completely different unit. The system only works because people are following the rules, not because they're capable of personally confirming their targets."
"Another, rather unique case concerned a Germanian city called Arene which was located close to the front lines and contained a central railway switching yard. ...that is, a place where trains - long distance freight transport technology used for army supply - are routed between the different tracks they run on. This area had been conquered some fifty years ago from the same nation we were now fighting and some of its population wished the enemy would reconquer them, or so it was later said. In any case, the enemy managed to sneak in a small elite aerial mage unit which took out the city's garrison and proclaimed the city to be in rebellion and that the population supported them."
"The military situation was already very precarious. If the railway junction couldn't be freed within ten days the front would collapse, with over a million men killed or captured and the nation presumably having to surrender shortly afterwards. My aerial mage battalion was part of the emergency response. We engaged the enemy unit inside the city but failed to completely eliminate it, since they dispersed and hid while recruiting disaffected locals as a militia. We rescued some people they were holding as prisoners, public figures who opposed their takeover, but that didn't really resolve anything... The Germanian army demanded they let civilians evacuate the city, and when some people tried to leave they shot them - we have recordings. We asked for parley to arrange to evacuate noncombatants, they refused and claimed the whole city was a militia united against the Empire. It was patently false, they were holding our own citizens as hostages against us with guns to their heads hoping we'd rather lose the war than fire on our own city."
"Command decided to call their bluff and instructed artillery to bombard most of the city outside the railyard. Several hundred thousands of people were killed, probably mostly civilians and not rebels who volunteered for the enemy's militia. The legal fig leaf of a justification was that we took them at their word and treated the city as a fortified enemy stronghold, but the reason was that the alternative would be to lose the war."
"My unit and I were there throughout. We didn't make any decisions that mattered to the city's destruction, we were following orders, and even to disobey those orders would have only delayed events by a few hours until another unit of aerial mages was sent in, or the army simply decided to proceed without aerial spotters. It was hard for some of my men, but - not in a way where a better alternative suggested itself to me. ...I was operating on the understanding that I would only be sparing my men the moral unpleasantness by burdening some other soldiers with them, and an army cannot function if all its officers adopt this policy. I did wish we didn't have to do this, but - only in the same way I have wished there didn't have to be a war."