I think if you are 'prepared' to kill someone then you have to train to kill someone (i.e. a neck break instead of irimi-nage). Although I know several potentially lethal strikes and techniques, and also mention these possibilities to other students, I do not train to carry out these techniques. Thus I doubt if I would ever kill someone without a real concious effort.
As mentioned, the level of force probably reflects the persons ability to control the situation. This is understandable, however I think fear is the big problem that makes us over-react or fail to help others e.g.
Kathryn Cole (Kat.C) wrote:
Well, I'm not willing to risk my life in order to preserve the life of someone who is attacking me, that's insane! I also don't believe it would be unethtical to kill an attacker is such a situation either.
I see your point Kathryn, and who knows what one will really do in a situation. However, who are you to say your life is worth more than theirs? I think this is why we should really reflect on the fact that we will die one day; and in my belief there is no heaven, so our actions are more important than our lives. Aikido give us a way to live without fear, yet still to be able to protect our lives.