True, much as "Mutually Assured Destruction" was supposed to prevent the use of nuclear weapons by the major nuclear powers.
It has been true in my own life. After a particularly heinous series of crimes took place where I grew up, my mom signed me up for a self-defense course at Cal State L.A., and I believe that it was largely because of my willingness to use what I had learned, combined with the increase in my self-confidence after taking the course, that led to my never having to put what I learned into practice.
RE: The Masculine Principle - The Right to Self-Defense