My dog is 130lbs. He has long hair and he looks like a wolf. He's majestic, beautiful, and terrifying to anyone who doesn't know that he's just a dog. His head is the size of a football, his snout is longer than my hand. He is very strong and his teeth are razor sharp, he once turned a possom into two half-possoms.
Being purebred, his genes are close to a wolf's and so he has strong instincts. The speed that he runs out my back door is incredibly, all to satisfy his urge to hunt whatever unfortunate critters may be in my yard. He's protective and territorial, natural instincts that can manifest into dangerous behavior; so it is very, very important to properly train a dog of this size.
His motivation for his domestication was the treats I gave him as a puppy. Food and shelter is enough to change the animal from a savage to a companion.
Immigrants should have something similar. Just like my dog is treat-motivated, people are money-motivated. In a normal world, an immigrant is rewarded with wealth and status if they behave according to the culture's expectations (getting a job and contributing to society).
What would happen if I gave my dog unlimited treats while raising him? He'd keep begging, keep eating, he'd get fat and I'd go broke. Worse yet, he wouldn't learn to behave properly and that means that he could seriously hurt someone. But this is expected. So why expect differently with immigrants?
We used to have poor immigrants who assimilated and contributed to the country so much that they are part of our history. Liberals say "immigrants built America" and there's definitely some truth to that (although "built" is a generalization). Now we have rich immigrants who don't need to get jobs. What do you expect?
I disagree with the argument that those poor immigrants of the past were from Europe so assimilation wasn't a huge change for them. It's not true. The Chinese who built our railroads stopped eating dogs when they came here, they did what they could to make a better life for their families which often meant working indentured in grueling conditions. There is an entire genre of Chinese films about Chinese immigrants balancing the new world with family and tradition.
I guess my point is that immigrants have no reason to assimilate. Why even learn English when the aisles at the grocery store, the menu at the drive-thru, the drivers license form, are all in Spanish? Why get a job when welfare pays for your 7 kids? It's more profitable to siesta a bang your senorita all day to make more Paco's and Juan's and Maria's and Titos.
The west is occupied.
I guess I was thinking more about organic assimilation. Of course you can get results with strong pressure over a couple generations, unless you're dealing with a population that actually lacks the mental capacity.
Not generations, immediate results. If we had fair systems that treated all people equally than our core western values would be defended. If they went to jail for crimes and needed employment to thrive than that's all it would take for them to stop doing crimes and start getting jobs. It'd be overnight, not "generations". When certain behaviors led to consequences while other certain behaviors led to wealth, people behave however is best for themselves or their families.
Natural assimilation, to me, means when assimilation happens naturally (duh). Like how different species of birds may flock together if it is mutually beneficials. Or how domesticated pets have assimilated into human households.
And IQ plays no role either; my dog behaves so well that I allow him in my home despite his savage instincts and low intelligence. Meanwhile immigrants behave so poorly that I don't want anywhere in my country, despite having higher intelligence than dogs, the ability to speak and learn, and every welfare possible provided for them.
Literally all it takes is them not getting free money and the criminals being arrested. If life here required work for them, like it does for us, than they wouldn't come anymore. Many would leave.