If you and I were to travel back in time to the high trust society before mass surveilance & enquired our police wouldn't deny they held the the monopoly on violence. My friends in the forces of today tell me they feel under siege most days.
Apologies, "London is the knife crime capital of the world." is part of the venacular here akin to "The man who broke the Bank of England".
Meaningless without comparison to other countries.
> London is the knife crime capital of the world.
Doubt it. https://en.wikipedia.org/wiki/List_of_cities_by_murder_rate