The problem is your definition of "white nationalism". The article explains the difference between violent white supremacy and white nationalism:
> Our policies have long prohibited hateful treatment of people based on characteristics such as race, ethnicity or religion — and that has always included white supremacy. We didn’t originally apply the same rationale to expressions of white nationalism and separatism because we were thinking about broader concepts of nationalism and separatism — things like American pride and Basque separatism, which are an important part of people’s identity.
Literally the next sentence you neglected to quote says this:
> But over the past three months our conversations with members of civil society and academics who are experts in race relations around the world have confirmed that white nationalism and separatism cannot be meaningfully separated from white supremacy and organized hate groups.
There is no meaningful difference between white nationalism, white separatism, white supremacy, and hate groups. They are the same thing. So... I mean... did you read the article?
That's the question I'm asking: if we accept that these beliefs are on a spectrum and that white separatism (or more generally pro-white politics) slide inevitably into violent white nationalism, who's to say the same doesn't apply to orthodox Islam? Specifically the above poster referenced Christchurch as an example outcome of the former, I argue you can't do so without considering the many examples of the latter.
White nationalism, white separatism, white supremacy, and hate groups are not a spectrum; they are the same thing. There's no difference.
There is a difference between orthodox Islam and extremist violence: just because some violent extremists are Muslim doesn't mean all orthodox Muslims are violent extremists.
You believe it's literally impossible for someone to advocate for separatism, pan-Europeanism, or protection of white culture without being a violent hate group?
Yes indeed! Those views inherently advocate for the genocide of non-white people (and even some people who are white but are "degenerate," like gay people, trans people, Jews, or whatever ethnicity they believe isn't sufficiently "white"). I do believe that some people don't understand what they've gotten themselves in to, but all white nationalism is essentially advocating for the broad extermination of many people.
> Our policies have long prohibited hateful treatment of people based on characteristics such as race, ethnicity or religion — and that has always included white supremacy. We didn’t originally apply the same rationale to expressions of white nationalism and separatism because we were thinking about broader concepts of nationalism and separatism — things like American pride and Basque separatism, which are an important part of people’s identity.