As long as there's one person in the world willing to use force to take advantage of another person, there has to be a mechanism for using violence to prevent that force. And to cut you off, no... passive resistance strategies will never work. Ghandi and MLK Jr. only achieved the success they did because they weren't actually trying to STOP violence, they were trying to call attention to a situation so that others would step in and stop it for them. Eventually you always need laws and people with guns to enforce the laws when they're broken.