In fact, if you look at these "low-trust" societies, all of them have some reason why they haven't been replaced by the high-trust subcultures that you mentioned, reasons usually involving guns.
In fact, if you look at these "low-trust" societies, all of them have some reason why they haven't been replaced by the high-trust subcultures that you mentioned, reasons usually involving guns.
I think Trust is not really one singular thing either, and it kind of falls apart when you look at places like China or Japan. For example in Japan people don’t generally fear petty theft of bikes or electronics, but they have women-only train cars and the government forces smartphone cameras to make a sound to prevent creepshots. In China you have the zero-sum “it is good for me when others fail” mentality but also Guanxi and genuine patriotism.
Probably technology and law enforcement does allow large scale societies to persist with extremely low trust, but the more concentrated power becomes, the more that state’s continuance is subject to the whims of a small number of people that could either change their mind (like Gorbachev) or fuck things up so badly that they get overthrown (Romania). I think it helps that leaders and police/secret-police also live within that broader low-trust society and so they do have some incentive to not make it too bad.
I consider law enforcement a critical part of a high trust society. I can operate a business and offer lower prices because I don't have to spend extra money on security to defend my goods because I trust that the law will punish thieves. Many times in society I won't do something because, e.g. speeding, because I know the law will come down on me for doing so, even if I know in the short term it would be advantageous for me.
A low-trust authoritarian state that restricts personal freedoms has to use heavy handed policing/secret policing with severe punishments to maintain that system. Without heavy policing the state would probably collapse internally.
A regular place needs policing to prevent the kinds of crimes we consider unambiguously bad like murder, theft, rape. Like I mentioned elsewhere trust/cooperation is game theoretical, and I think that shows up in our genes such that there are always some latent number of people predisposed to antisocial behavior. So you always need that.
But in the second case, the level of trust does reflect how much policing you need. If there is not much crime you don’t need that many police. You probably do always need some but the real world demonstrates that some places just have more criminality (low trust) and require more police.