You can point towards African communities and immediately debunk the whole 'leftism screwed them' argument because a huge chunk of that continent is being frequently fucked with due to militia and terrorist groups constantly fighting each other and governments being deposed.

Those militants are the Leftists... This is what happens when Leftist academicians start trying to "decolonize" Africa with Leftist ideology. This is what ethnic based revolutionary Leftism looks like.

Why do I bring this background up? I don't necessarily think it's to do with 'race' however I do think that it's something that's been deeply engrained into a racial culture which both leftists and white nationalists don't recognise.

It's not a racial culture thought, because there isn't a racial culture at all. That, in and of itself, is nonsensical Leftist bullshit. It always was, in all it's forms. You have ethnic cultures, but you can see the significant differences between each ethnic group in Africa (lo and behold the Zulu are more violent than the Bantu). Culture can be abstracted, at widest, to religion. But not race, because that strata of human classification is simply too broad and has no real influence on individual behavior (where religion explicitly does).

In America, the problem is that Leftism has effectively balkanized American Blacks into a revolutionary class that sees America as a bourgeoise state. You remove that, and you go back to normal levels of violence and crime.

You simply need to let them all know that you don't tolerate that shit in the country and then things will settle down or they leave/get booted out.

This is just true to every population.

They have frequent patterns of behavior that they pass onto the young generations. A more fucked up variant of this is the Afghanistan tribal communities etc. and these were people that the west was backing against the Taliban so no surprise we lost there supporting the paedophiles who had a thing for little boys.

Again, these aren't racial though (Pakistanis and Afghans aren't a race). These are cultural institutions that are continued by the culture of these peoples.