The moment you allow the possibility for someone to excuse or justify an act of killing, words and actions will be twisted and bent to serve individual needs. You are right George. Peace (i.e. nonviolence) is a crystal clear principle.
Unless you hold that people can be non-peaceful without being physically violent - that there are violent words as well as violent actions; fighting talk, insults, intimidating body language, etc. In that case peace can, given that some people don't recognise
how what they're saying or doing can be seen as insulting or demeaning or what have you, become incredibly complicated.
I daresay a lot of people just like the idea of being able to say whatever they like without someone rocking up and slamming a fist in their face. Though, at least in terms of principle, I'm inclined to think it works out more like someone said in a TV show once with respect to force - "You hurt me, I hurt you. I'm just more efficient at it."