"He who lives by the sword dies by the sword"

Killing is a sin. simple as that,

If no one killed anyone then ww1 wouldnt have happend

Thus all governments are sinful.

All humans are sinful. Can you go a day without killing an insect or a microbe?

This term "sin" seems so generic as to have no meaning at all.

There is death and killing, that was inferred after original sin. There is not much that can be done about that...

I didnt write the commantments

The point is that if everything is a sin, and every human is by definition a sinner, what's the point in saying that something is a 'sin'? That's moot (or redundant).

Thus, the statement that "killing is a sin" is a content-free statement.

I can see that your not a christian