And yet it seems like you're reacting the same way they do.

First you say that the problem with them is that they deny that other human beings are humans or animals since you say they lack empathy for another human being or even another living animal.

Then you deny yourself that they are either human or animals, and say that they should all be killed.

What if they hold the exact same reasoning, that their victims aren't humans or animals in the broad sense, and that it's OK to kill them?

Wouldn't it answer your question: "How is it possible that they lack empathy?"? Simply because they see their victims as humans or living animals, the same way you don't see them as humans or living animals and lack empathy towards them.

On that matter, Lévi-Strauss said that this habit of denying other human beings their humanity is a common tendency for all cultural groups in the History of mankind. In every community, you'd have this mentality of "Us", the pure, the true mankind, versus "them", the evil beings, the not-humans.

I'm not trying to advocate cultural relativism to justify their actions, and I do not imply that their behavior is equal to the behavior of any other cultural group.

I'm just really trying to find a ground for your position, and see if there's something more stable in it than a mere emotional outburst that self-contradict.

You could for example tell me that killing them is justified because they killed human beings.

However, this pilot tried and probably managed to kill of few of them, too.

You could say they started this killings.

However, a large part of their rhetorics includes historic references to killings of "their people" by "the others". That is that, in their eyes, they didn't start this killings, and are merely reacting to it.

Can you please give me a few other ways to solve this issue, so we could see if we are able to find a way out of it?