Historically, cops have always sided with the aristocracy/bourgeoisie/land-owners/those with money.

Because it’s that state which they serve, obviously.

There's a fundamental difference between cops in socialist countries and those elsewhere. The police serves the state -- with the exception of some individuals, they act in the interest of the bourgeoisie in capitalist countries and the workers in socialist countries. "ACAB" is implicitly limited to capitalist countries; otherwise, it would be akin to anarchists denouncing all states

Gonna lock this thread. Sorry but I don't think the OP is arguing in good faith.

Moreover this is not something that needs to be had intense theoretical debate over. There are AES countries with people living in them under the authority of their police. It would be more instructive to seek their opinion (though I admit it is not easy or straightforward) rather than mull over hypotheticals.

My reasoning is that it is a position of power over your fellow citizens/countrymen/people and only bastards would be attracted to such positions.

Wouldn't this then be true for any political position with executive power too? It seems like a flimsy criteria to me.

I apply ACAB to capitalist countries. Their police operate as organized crime that protects capitalist interests and occasionally their stated purpose to keep up appearances and a false sense of service. In these countries, bad cops are common and "good cops" all either cover for the bad cops or get hounded out of the department.

Not that socialist countries haven't had cop problems, but it really has been fairly different in them. They tend to divide up the duties of cops and split them among different organizations. Like... the traffic cop doesn't carry a gun and instead calls for help when they see something go down. There are usually fewer cops per capita in socialist-run countries. There is less need to protect private property interests when there is less private property in the first place. In addition, you don't need cops to dehumanize and eject homeless people in front of businesses when you virtually eliminate homelessness. You also don't need as many cops if you don't have a racialized drug war to prosecute or a cartel to fight.

If you go to Cuba you will find cops just standing around, hanging out, not intimidating anyone. They're of the community. It's not simply good or bad, but it's very different from the ACAB conditions experienced in capitalist countries.

Back in the 90's (no idea how that would be now), at Cuba. police was formed mostly by people doing its military service (which was, at the time, 3 years).
Many of my highschool friends worked as proximity police because of that.
So no, not all C AB.
Said that, I would say that there are a ton of material and social conditions to ensures that, at least in a capitalist country, the role is fullfilled by Bs.

Personally, I believe that A CAB. Yes, all cops are bastards, no exceptions. Yet I have met people who think that cops in socialist countries aren’t bastards.

This is framing the entire world in the lenses of western liberal issues, its chauvinism to a degree.

ACAB makes most sense in the west, american police kill 1000 people+ a year in cold blood and oversee the largest prison population in humanities history, slave labour and racial terror.

Chinese police on the other hand, have killed about 20 people in 30 years.... and typically in response to being attacked first, or in response to mass terror events. They are simply not comparable.

The idea is they too eventually get phased out, but it is base idealism to think you can vanish the police over night. They get removed because of contradictions leading to solutions, as marxists we should recongise this; even after the revolution, or seizing power, or gaining power; we will still need to defend it, we will still need 'police'; the benefit is there will be no landlords, so they will not serve the landlord class, and we will direct them to serve socialist interests (read althussers theory of the state apparatus, they are the club of the brain of the state)

Since our end goal is the dissolvement of the state, it comes to think they will be disolved too eventually, and it is our end goal; but you cant jump straight to the end goal.

It's a question of what is meant by "bastard". Does it just mean someone interpersonaly shitty or is it being used as a shorthand for a more specific political characteristic? In a capitalist society any cop is a class enemy by definition and therefore a bastard in the political usage of the word regardless of their individual character. Under socialism I would expect the role to still attract aggressive unpleasant people for the reasons you list but they wouldn't be betraying us for our bosses just by putting the uniform on.