I've noticed over the years that if violence is admitted as an option, it soon becomes the default option. If someone initially says they will only use violence in defending someone else, it isn't long before they begin to see violence as an option in self-defense as well. Violence is like a virus that takes over the whole thought process and makes it sick.
If, on the other hand, you start from the initial viewpoint that violence in never an option, it's amazing how many creative ways you can come up with to manage the situation. Once again, Lakoff and Johnson are correct, metaphors matter. How we describe things does affect the way we see solutions.