>

The US and Canada are immigrant societies, they've been taking in and integrating diverse ethnic groups for a very long time.  Sweden and Denmark, on the other hand, have been fairly homogeneous and insular societies inhabited by mostly the same people since the Dark Ages if not earlier.
And the US kind of got to practice on relatively similar groups (to the dominant WASPs) before moving on to more divergent ones.  Back in the 1700s, that meant German, Scottish and Dutch Protestants, then later European Catholics,etc. etc.  Whereas the inexperienced Scandinavians now have large numbers of Muslims from the Middle East and so forth, which is a more challenging situation.
I can think of 4 factors:

Language: English, French, and Spanish are present in tons of countries globally, whereas German, Scandinavian languages, Slavic languages, etc. have very little presence outside their home countries. People from Africa or the Indian subcontinent are highly unlikely to know any Scandinavian languages, and much much more likely to know English or French.
Merit-based Immigration: Canada has a point-based immigration system. You get points for having higher education, points for knowing English, points for knowing French, etc. More points, higher odds of getting immigration approved. Canada of course does take refugees, but most immigrants are pre-filtered to be ones who will likely contribute to society and likely not detract from society. Maybe the term "merit" is an over-simplification, but that's the gist of the idea.
Geography: Canada, UK, and Australia are harder to get to for people that don't already have some stability in their lives. They're obviously not impossible to get to, but it's easier to get from Africa to Italy than it is to get to the UK, and easier still than it is to get to Canada, the US, or Australia. If someone from India is going to get to Canada, they probably already have means and some stability in their lives, or an existing support structure in Canada who is helping them out.
Ethnostatism: Many countries are, by default, ethnostates. Their lands is the land of a particular ethnic group, with a particular language, and a particular culture. But countries like USA, Canada, and Australia in their current forms are not like that. These countries obviously have indigenous populations but they don't run those countries' governments. American is not an ethnicity, it's not a language. Immigration to America is not as existential a question for America as it is for most European and even Asian countries. Another way to put this is that America, Canada, and Australia are "nations of immigrants" whereas most countries are historically nations of a particular ethnicity which happen to have immigration. >

I think you're spot on, especially with point 4.
I do have one small, pedantic nit to pick with point 4 though. What you describe there is a nation-state, not an ethnostate. An ethnostate is one where citizenship is restricted to members of a particular ethnic or racial group. >

I'm not aware of the nuances of the argument, bit I had a related quibble with item 4. Great intellectual argument, but to me it just boils down to ' not used to foreigners'. Now you can argue why, bit that is the basic.
I feel the same way when people describe Sweden or Netherlands as liberal. Now there is nuance in that argument, bit to me those cultures tend to be inherently conservative, with the huge exception of what YOU do is very much your own business, not something for them to weigh in on.. >

My assumption for Canada, Australia and the US is simple: they’re not native to their continents. Americans, Canadians and Australians all are immigrant societies. So over time they’ve all developed strategies for embracing outsiders.
The UK you could argue as a byproduct of their vast Empire, it was bound to import talent from all corners of the Earth when it could, and therefor eventually has its own style for integration. Also the UK has always made it a thing to not be “lumped into” the “European project”.
Europe has very clear and historically formed borders through a lot of blood and conflict and so their sense of identity is a little different and while European identity is a thing it’s definitely more rigid than Canadian or American identity, for example. >

Am British. We used to describe ourselves as a mongrel nation. Historically we were invaded by the Angles, Romans, Saxons, Vikings and Normans. We’ve been ruled by Germans. The Spanish sent a fleet against us which was wrecked, and the Spanish sailors integrated. 
Then we had the empire and people came from all over the world.
Nowadays we have lessons in school about multiculturalism. It’s a massive deal and really important to us. >

Then why'd you send all those refugees to Rwanda? >

To be fair, we haven’t actually sent any refugees to Rwanda. >

plan to. My bad, I wasn’t aware of the court delays >

The home office wants to send them there to discourage dangerous small boat crossings. It's with the courts at the moment. 
There's a big problem with human traffickers in Calais sending folks out in little boats with fake lifejackets. Lots of them don't make it. I don't think this is the right solution though. >

A big difference is the starting point. Canada and the U.S. were never completely a common peoples with a common culture compared to some Northern European countries. "Assimilation" in Canada/U.S. might just mean assimilating to a regional subculture or a particular city's subculture or an ethnic subculture in a big city like New York City. There's always been some wiggle room (especially in the U.S.), even if it was at the margins. Less than one generation might be enough to sufficiently "assimilate."
Since Northern European countries are much more homogenous, "assimilation" is a higher bar and might mean adherence to a very specific culture (even down to how people look) in a way that is nearly impossible for an outsider to really achieve. Even for second gen+ immigrants. >

I don't buy this. Italy only unified in the second half of the 19th century and the various states and regions still have distinct culture and pride for their particular region that is as strong as you see in the US. The history of Germany is all over the place and is deeply connected to empire and there are deep and enormous cultural divides between primarily catholic and primarily protestant regions. 
Neither of these countries are scandinavian, but both have similar anti-immigration sentiment within their politics. >

That may actually strengthen point 4. As you point out, Italy and Germany didn't unify until the 18th century. Because of a lack of historical continuity for these states however, their founders attempted to tie these countries together with the idea of a shared nationality. The concept of nationalism and nation states were actually first coined to describe the process by which both German and Italian speaking states unified in the late 1800s. >

But this is true of the US too. >

Nope.  Not in the slightest. >

The US is a nation of immigrants and, regardless of what’s portrayed in the news, one of the most immigrant friendly nations in the world. Most eastern (and most European nations) are surprisingly racist compared to the US just because of our high tolerance to racial issues due to our past and high levels of immigration. I’ve met plenty of Americans who’ve spent time in either Japan or South Korea who have been surprised at the level of racism towards anyone who wasn’t Japanese/Korean >

Having lived in the US and the EU, I would agree. I saw a lot of Asian hate in Europe, a gay couple get jumped in Prague, etc. No place is perfect.  
However, I do think we need to make legal immigration more attainable in a reasonable time frame. Of course I want safe border control, but I want merit based entry accessible for desirable individuals and families. I think Canada has a beautiful model. >

It is a lot harder to get into Canada than America.
But I agree we could use a system  like theirs. I think the dems fucked up pretty hard taking the stance that opposing illegal immigration is racist.  Not sure they will walk that back >


It is a lot harder to get into Canada than America.

It's the complete opposite. It's a lot harder to get into America than Canada. Just look at the foreign born % of population in each country. Almost a quarter of Canada's population is foreign born, but only 14% of America is. That number is compatible to the UK.  In addition, Canada's yearly intake is way higher, with a target 500k this year. That's equivalent to around 5M down south. Many people migrate to Canada because they found America's system too difficult. >

Canada flung its doors open to higher-skilled immigrants from around the world, because it didnt have nearly enough of its own.  They scooped up lots of Eastern European engineers and other skilled laborers in the 90s.  Lots of people from my home country wound up there.  Fortunately my family got into the US. >

Because Scandinavian countries are part of the Old World. Canada, Australia, New Zealand and the US are New World counties, formed by colonialism, that have relied on immigrants for decades (centuries, even). 
UK is part of the Old World, but a lot of their immigrants are from the countries that they've colonised over the centuries. >


UK is part of the Old World, but a lot of their immigrants are from the countries that they've colonised over the centuries.

What do you make of the situation in France? France seems very diverse with lots of people from Africa but I hear many immigrants live in the suburbs/banlieues with lots of crime and poverty. >

I don't know too much about the French situation in particular. Historically speaking, the French have always been very protective of their culture, especially their language - something that's very evident in Quebec as well. But, as I said, I'm not too familiar with France's immigration and integration policies. At a distant glance, it looks like it needs a lot of work. >

There is a difference between immigrnats who wnt to come to a place, stay there and build a life, and refugees from a country at war who plan (and do!) to go back as soon as the war / acute danger is over. These people see their stay as temporary and have therefore a lot less incentives to integrate. And of course they are culturally very different in many cases. That is not the case with the majority of immigrants in the US/Canada. The fact that it seems to be easier for Ukrainian refugees shows that culture plays a part. >

That is a noticeable part of previous Latin American immigration, both legal and illegal prior to cartels and gangs taking over. Come to America, live cheap and stash a bunch of cash and build a home down there, then head back.  Assimilation wasnt as big since they didnt plan to stay here forever.
NAFTA, cartels, and stronger borders made life there harder and pushed people to stay here more.
Its common for lots of other immigrants as well.  Come here for the good times and money, then head back.  As an immigrant, my family gave up everything to start over here so we assimilated fast and good.  We've cut off people from back home who just loooove the old country. >

There's clearly a systemic failure at play here, first off some background:
In 1980 about 1% of the Swedish population was born outside the West, today about 10% of the population is made out of refugees and about 20% of the Swedish population is foreign born. If we add people with one parent being foreign born, aswell as second and third generations immigrants you quickly realize that this is a seismic shift in demography that happened in a very short timeframe.
In fact I'm unsure if there are any parallels anywhere else in the world in terms of how fast and how seismic this shift was. I don't think this can be underestimated as a baseline in explaining the change in Swedish society and politics towards more restrictive immigration policy aswell as some of the integration issues.
Secondly, it's important to understand that the extremely liberal immigration policy Sweden has pursued for the past 30-40 years or so was sold to the electorate as an investment and a net profit economically. The truth is that it isn't and hasn't been for some decades now, the reason for this is there has been a shift in immigration from labor migration to mainly asylum seekers. 
Now that doesn't necessarily have to be a problem, if Swedish politicians sold it to the populace as a humanitarian venture where we could and should shoulder the cost in solidarity. But they didn't do that, now couple that with the fact that there never has been widespread support among the Swedish electorate for this type of immigration policy and you can begin to understand why a party like SD could gain a foothold.
So why is integration bad/worse than in other countries (which I think it is)? I'll list a couple of points I think contribute and someone else can chime in if they want:


There really are no low skill jobs. Almost every job requires secondary education in Sweden.


Swedes are notoriously hard to get to know on a personal level


There's been a naive belief in the state and institutions as mechanisms for integration, rather than society as a whole


Lax or no rules for where immigrants could settle, leading to isolated and homogeneous communities where no Swedish is spoken 


No demands for learning the language or getting a job in return for citizenship or permanent residency


Generous unemployment and child benefits (increasing with each subsequent child) on par with what a working wage would net you


I don't think it's a resource issue. Enormous amounts are spent on "problem areas" and schools to no avail, the issue is I think more in the top down approach. Integration has to be organic and in a way community/society driven, and I don't think Swedish society can cope with integrating the sheer amount of people. >


about 20% of the Swedish population is foreign born.

Mostly that's freedom of movement within the EU. >

They have a culture failure to integrate immigrants. 
America is good at making people.....american. It is one of our best skills that is not ever really talked about.
There is something about our culture that anyone can come here and be american. We dont really have the pockets of immigrants that didn't integrate like the EU does.
Despite the massive amount of propaganda flying around. America is still a country of immigrants and true patriots know and understand immigrants coming here from all over the world to become american is one of the most beautiful things. >

I might have a better way to articulate that; Id say it’s not that America is about making people American, more that the scope of what it means to be “American” is insanely more broad than what Swedes for example likely consider what it means to be Swedish. >

I'm hesitant to speak for the other countries, but as a Canadian I can say that we have a massive advantage in successfully integrating our immigrants in that no immigrants can simply walk here. Every immigrant that comes here comes by plane, with express invitation to do so, and we get to pick and choose exactly who we want. I imagine that makes it way easier on us (and I guess same with Australia and NZ) than it does on European countries or the US, which has tons of migrants just walking across their borders. >

When you go to European countries, a person could live in a country for 5 generations but still not be considered that nationality.  You can look at France for an example.  People not even born in the US will be Americans within 5-10 years of immigrating. >


When you go to European countries, a person could live in a country for 5 generations but still not be considered that nationality. You can look at France for an example.

That's not true in France. French people consider it offensive and racist if you suggest a non-White person who grew up in France and is French citizen as "not French". There was an uproar when Trevor Noah suggested Mbappe and other Black players were "African". >


extremely traditional Muslims do not integrate well anywhere. Period

Well sure, but their kids can.
Consider Muslim Millennials in ths US. 52% of them are first-generation immigrants, and most of the rest are second- or third-generation immigrants. A 2017 Pew survey found that "Muslim Millennials are more likely than older American Muslims to say homosexuality should be accepted by society (60% versus 44%)," that "just three-in-ten Muslim Millennials (27%) say homosexuality should be discouraged by society, compared with 39% of older Muslims," and that in the US, Muslim Millennials are more likely to vote Democrat than older Muslims. >

I think it’s the opposite sometimes - many first generation immigrants remember how crummy the country they left was. Their children don’t, and their children are raised to consider their new culture as haram. There have been several terrorist attacks committed by 2nd generation muslims >

Probably that 27 percent mentioned.