Obviously someone actually attacking with lethal force is go time. Actually, I would argue it is a sign that "go time" happened previously. Regarding the "do I need to?" questions those are always variable. I tend to preach staying mobile, NOT getting into a terrible tactical position, all while trying to get enough information to make the decision. Just something as simple as aping Jeff Thompson's "Fence" concept while trying to circle the "might be a threat" at least 45(but preferably a bit more) so that peripheral vision picks up the previously blind spots seems to be robust and work half assed reliable. I also stress that someone not letting us do that isn't being "polite" or "innocent". That is "information" which informs the choice to go violent/loud.
As far as the lethal force "lines in the sand" I really, really like Kathy Jackson's list. She describes these as conditions under which she "intend(s) to fight back even if I don’t think I can win."
Quote and List from her site:
Some of my personal boundaries are:
I will not go anywhere at gunpoint. If the bad guy wants me to go somewhere else, it’s because he will be able to do something to me there that he is unwilling or unable to do to me right here, right now. Therefore no matter how bad the tactical situation seems right here and now, right here and now is the absolute best chance to fight back I will ever have and I intend to use it.
I will not be tied up. If the bad guy wants to tie me up, it is because he wants to do things to me that I would be able to prevent if I were not tied up. Therefore, I will resist while I am still able to do so.
I will not kneel. No one is going to execute me. If I die, I’ll die fighting.
If someone tries to take one of my children, I will fight even at the risk of my child being killed in the resultant firefight. I plan this not because I have positive assurance that I would be successful, but because I would not be able to live with myself if I simply “allowed” my child to be taken, brutalized, and his body perhaps never found. I’d rather watch him die in front of me. (Yes, that’s harsh … but given those two options and only those two, which would you choose?)
My point is not that your boundaries should be the same as mine. It is simply that even though you can wait until the very last moment to make the final decision about fighting back, you should have certain things already set into your decision-making machinery beforehand. If you don’t, and if you are ever attacked, you may not have enough time to do anything but stand there with your brain frozen solid while your attacker takes all your choices away.
I will add that my exception to the above is when dealing with someone I reasonably believe is law enforcement.
Great to hear about Little Sento.