Back in the 1970s, I would occasionally go bar hopping in South Tucson. Although it wasn’t a particularly rough neighborhood, there was always the potential bad guy. As a recent Vietnam vet, I was always doing threat assessments. My head was on a swivel. Seeking some protection, I considered a variety of possible weapons but rejected most of them. I was very concerned about possibly over-reacting and attacking someone who I perceived to be a threat but injuring an innocent…