Murder is evil. Killing someone in self defense is not evil. Killing someone like Hitler is morally good.
That said, would it be OK to kill innocents to kill a Hitler? For example, would it have been morally OK to nuke Berlin to take out Hitler (assuming the USA had the bomb earlier)? The Laws of Armed Conflict try to make sense of such things.
The author wrote: Taking any human life is evil...
I wrote that I disagreed with that statement.
It was a simple comment, and I did not think it would elicit pointless rhetorical questions about the moral dilemmas associated with war and/or defeating evil.
I guess I give people too much credit for being able to interpret the meaning of my comments.