Eh. That was still a military target and they didn't even do collateral damage(initially anyway, fire and smoke probably caused some though.) This is absolutely nothing. At most, it's a bit rude.
The empire isn't invading btw, it's getting invaded. The North Entente troops just walked over their borders(no matter how disputed those were, that's still an invasion.) Then the French Federation joined in, both materially aiding the Entente and attacking(again, invading the Empire's territory) the Empire to keep the Entente from falling. Then Dakia, wanting to take advantage of the situation and probably just occupy some more land to demand concessions out of the Empire, thinking they didn't have the power to spare down south, walked troops over their borders and invaded them from the south-east. And now United Kingdom is supporting Entente with materials and studying the Empire.
Quick math puts us at three invasions against the Empire. Zero invasions by the empire(in the timespan of this series anyway.
Yes the title would match that as it translates into War story or something but with so much inner dialogue and personal scenes with the Asshole X included, it doesn't really seem to work that way. (Auto)biography maybe?
Yeah, when anyone says you could have just disobeyed the order, you know they're just spewing bullshit. I can't speak for all militaries but generally, if you're ordered to do something you shouldn't due to international law or morals or something, you need to express your disagreement to the order, ask for it in writing and execute it.
So if your superior gives you and order to execute all your prisoners, for example, which is against the Geneva conventions, you tell them it's wrong to do so and you disagree, then you ask that he writes it down and signs it, then you execute all the prisoners. Later if it goes to court you're supposed to present the written order and testify that you were ordered to do so. After that point, the blame lies with your superior, not you.
If you were to simply refuse to execute the order, you are to be trialed in court martial for disobeying orders. Which in wartime, as you noted, generally means to get shot for desertion.
Of course none of this matters after the war if your side lost it since the enemy is going to execute everyone it bloody well wants to anyway, regardless of all the evidence and the fact that they know this just as well. The reason for this is that the people back at home(unlike most people actually fighting the war), don't regard the other side as people. They regard them as non-humans that they want to see bleed and die for revenge. It's very easy to de-humanise people you've never met.
The point about it being just a calling name for her is probably the best notion brought up in this thread yet. I hadn't even thought of that and looking at the comments, so had no one else. This would make a lot of sense.