Many years ago, I considered myself a pacifist. As a teenager, I dealt with a father who avoided culpability for abusing me by sicking my older brother on me and standing back watching. I would run from the fight, and when my brother would complain, I would protest that I was a pacifist and wouldn't fight. My father, the consummate liberal, sneered, "A REAL pacifist wouldn't RUN from a fight".
And so I stood there and took the beatings, without fighting back. Which is, I believe, precisely the effect he hoped to achieve.
As I neared 18 and filled out my Selective Service registration, I kept my philosophy in mind. I registered as a conscientious objector, being willing, however, to serve my country in any way that did not involve the use of weapons against another man or woman. As I have grown older (and hopefully, in some small ways, wiser), I have refined my views of pacifism to realize that I am not a pacifist, nor do I aspire to be.
I have, however, taken a personal vow of nonagression, which is quite a different concept entirely. While I will never take up weapons against somebody preemptively, I will not hesitate to defend myself, my family, and my freedom. I won't be that teenager standing by tasking punches while my sanctimonious father stands by laughing and chuckles about the incident years later at family gatherings. In other words, I will not be a victim.
In other words, while I personally detest violence, I will never rule it out as a last resort.