Karate is what you make of it. You can choose so simply block and avoid a potential assailant, rather than strike them into submission. You can train in judo or a similar art instead, which emphasizes immobilizing an opponent with grappling techniques. You can take track and field, and run faster than your assailant. Karate teaches body control, which is applicable in any physical endeavor, and is useful for many things besides fighting. If you have confidence that you can handle yourself in a confrontation, you will stay calm more easily, and be better able to handle the situation, and possibly avoid fighting altogether.