LOL, nozh, you are so right!
The use of a small folding knife in the chronicles of self defense comes to one conclusion - it's a rare thing, and a poor choice. Very few military ever train in the use, and I believe more police officers in a major urban area have experience than the world's soldiers combined.
The factors involved in self defense are the same ones developed over thousands of years of combat - get as much standoff distance as possible. Make it as easy for you to defend, and as hard for the opponent as you can. Therefore, the cardinal rule is to get a personal defense weapon with as long a reach as possible.
In the 4" folding knife, about the only criteria worth discussing is having training, and a knife with a reliable lock. Training is going to have to make up for major deficiencies in reach, standoff, and a complete lack of stopping power - unlike the "folder" nozh linked. In the most commonly referenced scenario, the victim is suddenly attacked with no warning and extreme speed in deployment and instaneously stopping the attack is the goal.
Well, you're already too late, you shouldn't have walked into situation to begin with, regardless of the weak justifications and "I had to's." Remember the rule is standoff distance - and if that means not even physically going there, that's what you do. It's why people move out of neighborhoods, leave their state, immigrate, whatever it takes.
Those that stay behind get folders like nozh's because they finally realize it's what's required.
As for tactical, any non-shiny knife made for hard use will do. Buy the best you can afford accordign to the actual features you prefer - flatground vx hollow, drop point vx whatever, framelock vs backlock, g10/ Ti vs stainless, straight grip vs. dropped butt.
Those choices are specific - that's what the better hard use knives have, blade steel is actually not so important in that range because it will be S30V, ATS34, AUS 8, etc.
The features you can use and actual training in bare hand combatives is a major step to being able to have any proficiency in self defense. Bare hand disarms are probably highest on the list - because you can respond instantly with them, and usually have no choice in the sudden attack fantasy. What knife you might be able to access rates pretty low, so buy what you like - you'll be using it to cut down boxes and spread peanut butter, mostly.
. me and a buddy were just talking about it today, how it looks like a pure stabbing machine.
