Nope.

Bomber Command in WWII and the use of nuclear weapons in WWII are both examples where you will find nuanced, intelligent debate on both sides of the argument of whether "mass, intentional killing" being wrong or not. What you describe as "hate / pride for his country" ... but isn't that the reason most soldiers kill? That you even bother to call this out shows that you know the reasons for killing people need to be taken into account.

I'm not making a statement on whether or not mass killing is wrong here, simply pointing out what seems obvious: it's far from black and white.

I'm sorry, but this sentence contains already the problem.

In shooting war, both sides have already ceded that killing people is morally justified.

And now you're in the unenviable position arguing about how much death is too much, and what are the proper ways to kill people in a war setting.

And then you get asked moral dilemmas if killing 100,000 people is okay if it saves 1,000,000 people from dying further. This is the Hiroshima/Nagasaki question in a nutshell.

I don't know that answer, but then I didn't fight a brutal war for four years, watching my friends, family, and countrymen die at the hands of a brutal regime.