Learning to kill

I practice karate and have been doing so for many years now. It struck me yesterday, when I used an Iaitō (metal sword) for the first time, that I am learning what would have once, in some form, been imperative to being able to stay alive.

I don’t really have to worry about that in my life (although knowing such things could come in handy in a sticky situation). But I find it incredible to imagine that there was once a world where knowing how to kill and how to do so efficiently was actually a practical skill to have.

Of course so much must go on behind the scenes; like the anti-terror squads and not to mention the soldiers who are killing people on a daily basis. But those are things that I could very easily turn a blind eye to in my world (until they happen to me of course).

In my world killing is wrong; not only because of the law but because it also feels wrong in my bones. I have been taught that life is sacred and, although I am atheist now, the moral teachings of my childhood still ring true.

Did the men who were trained to kill feel the same? Did they view life as sacred like I do now? Where does the idea of life being sacred come from?