So a couple years back, my apartment neighbor comes down and tells me and my wife that 15-20 methed out teenagers are en route to our building to stomp her younger sister for telling them something they didn't appreciate. I asked if they had called the cops and she said yes, but as they were not actually there yet causing a disturbance they were not able to respond.
Okay, so now is the time to stage a few weapons in key places, i.e. home defense in depth.
A little background on the family about to be threatened, teenage girl lives with 20 yr old sister who has 3 yr old daughter and they live with 50 something yr old mother. Lotsa women, no defense plan on their part. They came to me cuz I'm an army scout, my other neighbor, commo guy in army with wife and 2 yr old daughter, and my family: wife and 1 yr old daughter.
So lo and behold, yes close to 20 very loud and very worked up males with a couple girls most certainly do show up at my apartment building. The neighbors head inside, thus working the group up even more (they believe the teenage girl is to scared to take a beating, I'd agree with that as well as call it smart). As soon as this group has arrived my wife is on the phone with 911, she is armed, but not drawn. My army neighbor comes home at just this time and has no idea what is going on, but he wants to de-escalate and I have to drag him inside to let him know that that's not going to happen.
Now I have a Mossberg 500 back then, and I did have it handy, but I stayed out of it all until the group started threatening my wife and beating on the girls' door and destroying the flower pots they have outside of their door. At this time, I figure things have gone too far and I don't hear sirens in the distance yet. So step outside to where I am visible to all, I have my S&W m&p as backup with my Mossberg as primary, and I rack the shotgun and yell, "this has gone too far, cops are on their way, and you need to go now!" Well... needless to say, situation definitely defused because all the aggressors dispersed back to their respective vehicles.
I went back in my house, cleared my weapons and waited for the cops to arrive and I even waved them down. I told, along with half the neighborhood , the cops what had happened, my actions, and when asked, handed over my weapons to have serial numbers checked. A few minutes of standing by myself and the cops told that I didn't have to worry about any charges, that they and their supervisor believed they would have done the same.
Did I escalate the situation, absolutely. You don't show up at someone' s house with 20ish people and try to break an old woman's door down who has her daughters and 3 yr old child living with her, and you don't threaten a total of 3 families all with children and expect that no escalation is going to occur. Did any real violence occur? No. Did I stop what was turning into a very deadly situation decisively? Yes. And I did make sure to keep my weapon pointed at the low ready, not leveled at some tweaked out high schooler's chest.
Threat of Force, was enough of a deterrent to stop a bad situation, which as taught in the concealed carry course I took, is a method of de-escalation.