This should be taken within the greater context of one's perception of being "humane."
For example, if we are talking about making the decision to commit to a war of conquest, then we are already deciding that our wants or needs come ahead of whomever we are about to conquer. The question, then, becomes one's view of the post-conquest environment.
For example, when Japan surrendered to the U.S. in World War II - we handed them their Constitution and told them exactly the way their government was going to operate. We got rid of the emperor and fragmented the fealty system as well as dismantled their military capability.
Why? Because the idea that Japan would, 20 years later, pull a Germany was just what we saw happen in Germany. Germany was allowed to remain an independent nation and was simply slapped with trade embargoes and other restrictions in an attempt to keep them from building up a military... which worked out really well in the grand scheme of things, considering Germany started another world war.
For the record - Japan has not invaded any pacific islands in over 70 years. The argument can be made that the 'inhumane' decision ultimately worked out better in the long term.
That is what people mean by "reality" when met with 'inhumanity.'
We can go with another scenario - a child is running toward you with a live hand grenade handed to her by her parents who are Vietcong operatives. That's a more simple situation to work through, logically - the child is dead in either case, you just determine where the grenade blows up by putting an end to her forward progress. Still - that child could have been somebody.
From a different standpoint, the reality is that ideologies will often conflict to lethal ends. Typically, the issue involves control of some form or another, but when someone asserts control over you or something you need in order to live your life as you would like - you have two options. You can either acquiesce and permit them to have control - or you can reject that insistence that they have that control. Typically, this results in people willing to resort to lethal means. You either have the will to kill all who would attempt to control you unjustly, or you will be controlled unjustly. That's about what it boils down to.
On the other end, if you don't have the will to enforce the control you claim to have, then you do not have control. If you are going into a war zone as a 'peace keeper' - then you pretty much need to be willing to cripple both sides of the war, or have already chosen a side to destroy until it complies.
It depends on the situation.
Cold blooded mass murder in the streets just for shits and giggles is obviously ****ing awful.
But war crimes happen. When you enter war and you live with the fear of death constantly and see your friends and comrades die all around you, you can become an animal, especially when people tell you being an animal is okay. That's not a justification, it's just what happens in war on all sides. That right there is a reality, and we hate it, but we can't stop it because deep down we all have the capacity for animal-like evil.
No person can say what they would or would not do in that situation until they have entered it for themselves and under the same conditions. Until then everything is only speculation.
"Oh I would never do such a thing!" says Johnny. Yeah well Johnny has never had to kill people in order to survive and he's never had to see his friend's brains blown out by sniper fire and Johnny has never had to experience the general horror of war.
The only thing we can do is try not to fall into barbarity, even though we as a species can be/are disgustingly barbaric.
But anyway, sometimes inhumanity is unavoidable. Sometimes.
Morality is subjective. The fact that OP and I disagree 100% on the Uchiha Massacre is a good example I think. He believes, for various reasons, the Uchiha should have lived. I believe they should have died because, in my view, so many more lives were hanging in the balance.
We both think we're in the moral right but we have conflicting views.
