I like Drew's answer, training to give oneself choices. I believe that this is what Saotome Shihan has been teaching for years, that one cannot truly choose to be nonviolent unless one has the capability to be violent.
I would add to this the point which I was taught by Endo Seishiro Shihan. One must train to develop the ability to keep what Endo Shihan calls "everyday mind" at all times. If we panic under stress, the choices we might normally have, largely disappear.