I carry a firearm ...
It's really interesting how wearing a firearm has changed by thoughts about martial arts, distance, conflict, and even living in general.
This is a tough one. The possibility of escalation is so great and the outcome rapidly approaches terminal.
Lest we not fool ourselves please consider a recent event in Oakland where a father and son are 'king hit' out of the blue (according to the story so far) and the father falls striking his head and soon died from the head trauma. Seemingly out of the blue random crime with one punch becoming fatal. Not a hypothetical but 'pulled from the headlines' from a place I've walked many times - my favorite sewing machine/vacuum repair shop is right around the corner. No time for deliberation or observation and precious little time to draw a weapon or even bother attempting to intervene.
The real question for me is the case of these two fellows (the 'perps') most likely were not out for blood but just for kicks and I'll wager they have done this type of thing before. What if by not 'stepping in' this type of behavior is allowed to persist, grow and 'blossom' into fully fledged social pathology that wrecks many lives and possibly worse? It seems the personality type is emboldened by each event and unless checked (maybe even in spite of) grows more terrible.
If we are to believe that aikido (or your favorite 'do' art) is to help build a better society then either we all must train or those that do train must become more active in society. Which is more likely - all train or become active? I know, I can tend towards idealistic day dreaming but sometimes my blood boils and I'm compelled to act.
As for having kids around as an excuse/reason to stand off ... I'm of two minds. What kind of impression is left on the impressionable young minds seeing the 'bad guys' (as my son calls them) left unchecked versus seeing dad play 'good guy' and deal his brand of justice? Sometimes all that is needed is a firm word ... one time it did escalate to a face off but the old indomitable spirit was with me and my steely gaze was enough to quell to situation. My kids didn't even seem to notice that anything had happened ... or the wife for that matter.
I'm not advocating vigilante action but 'we the people' means all of us. If 'someone else' is expected to step up then just exactly who are 'they' and what does that make 'us'?