Rule of Law
In theory, we are a nation ruled by law, not dictators or bullies. Reality is another matter.
I'll never forget the time I saw a man gunned down in the street by about 5 or 6 police (this happened on the Peninsula).
I was getting off the train, and on my way home, noticed an inordinate number of police, who seemed to be just hanging out on the street corner, chatting. One of the police approached a man in the middle of the street. I couldn't see what transpired, but it was not a physical altercation. The policeman stepped back, the man in the street looked bewildered, and the five policemen opened fire.
I pretty upset about the event, because I was almost in the line of fire, and had to get behind a car. The police had little regard for anyone standing nearby, and no interest in witnesses.
Some time later, I read a newspaper report that a man had robbed a nearby pharmacy, and when the police encountered him, there was a struggle, the man took a police officer's weapon, and was subsequently shot. That was the police version of the story.
My version is the police acted as judges, jury, and executors. If you shoot suspected criminals on the spot, it sends a strong message to would-be robbers. Just like in the Middle East, where they cut off a finger or hand. Except, what if someone was actually not the criminal ? Justice means a fair trial, but I would guess that most police officers don't really believe in fair trials. We know our president doesn't believe in fair trials.
Once most citizens no longer believe in fair trials, or at least strive for that ideal, the experiment in democracy is over.