Kitten chases bear into a tree.

I recently told Marilyn that "I walk softly, and carry a big stick". When she asked if I was referring to a handgun, I said no, I do not carry any weapon on me.
My "big stick" is my ability, and obvious willingness to resist. Obvious, as anybody who crosses me will quickly catch on that I will not let anybody walk over me. I do not seek conflict, I do not like violence, and try to avoid it. But if trouble seeks me out, I will fight back!

Foolish? Well, *my* ability to fight off your garden variety punk has unfortanately been tried and tested, and it passed. Not a pleasant experience, nothing I would ever want to go through again, or put somebody through. On the bright side, aforementioned thugs will be less likely to be picking on other people now, being confronted with fact that some might fight back.

Criminals, and other attackers often rely on scaring their victims. They hope to scare their target into compliance, not expecting resistance. Being willing to stand up for yourself is very important, and showing the willingness to do so may scare off aggressors far beyond your ability to actually fight, as illustrated in this story where six month old kittens chased a bear up a tree! That's a six foot, 200 pound bear chased up in a tree by a little puss.
Rob Allen posted a tale of a cornered mouse willing to go toe to toe with a fullsized human, just to show an even more extreme picture.

I dislike violence, and believe we must work to build a peaceful society, but laying down your arms and giving aggressors what they want will not accomplish this! Preventing violence by showing the will to resist is better than getting mugged. Fighting of an attacker is violence in itself, but beats further cultivation of a thug who believes that his victims are easy pickings.

Suppose so many people start to carry concealed weapons that criminals become afraid to mug people, what then? Will they suddenly turn into law abiding citizens? No, they'll probably turn to shoplifting and burglary, but at least they won't be threathening people at knifepoint anymore.