> They were primarily concerned with Pan-Germanicism.

If that was the case, then why did their policies include the murder of millions of German-speaking Jews, Gypsies, and people with disabilities. What was it about those people that made them not fit the category of "German"?

The answer from clearly documented history is that the Nazis systematized the categorization of humans on their deeply flawed model of the Aryan "race", and singled out those who didn't fit for subjugation or extermination.

Conversely they also planned to further "purify" their own people by planning to subject Scandinavian populations to forced interbreeding programs upon conquering them, and kidnapping "Aryan" children from neighboring countries.

https://en.m.wikipedia.org/wiki/Lebensborn

https://allthatsinteresting.com/lebensborn

> If that was the case, then why did their policies include the murder of millions of German-speaking Jews, Gypsies, and people with disabilities.

Because Jews and Gypsies weren't considered ethnically German. Re: disabilities, it's a mix of rabid utilitarianism (they were called "useless eaters") and a belief that disabilities stemmed from corrupted bloodlines (hence the term mongoloid -- it was a popular theory that retardation was the result of Europeans/Asian intermarriage).

> Because Jews and Gypsies weren't considered ethnically German.

What defined German ethnicity?

Clearly it wasn't the ability to speak the language, or being descended from many generations of ancestors living in Germany, otherwise the Jews and Roma both would have been considered German.

Clearly there was something else attributed to them that didn't fit the definition of "German". It was that they weren't considered racially German. Race is literally what the Nuremberg Laws were about:

https://en.wikipedia.org/wiki/Nuremberg_Laws

https://en.wikipedia.org/wiki/Racial_policy_of_Nazi_Germany

Given the preponderance of clear historical evidence for the Third Reich's racially based rationale for its actions, one wonders why would anyone try to water it down to the more innocuous seeming rationale of "German ethnicity".

I'm not sure I understand your contention. Pan-Germanicism was about uniting ethnic Germans. Are you implying that there's no ethnic difference between a German and an Ashkenazi Jew or a Romani?

No, I'm saying that the way that the Nazis defined German identity was their biological model of "racial" classification, and not a cultural feature like ethnicity. The Nazis then (as today), have an explicitly biological notion of identity, not cultural.

I'm not making that up - it was right there in their laws that I linked to.

Otherwise, why shouldn't people who had been living in Germany for generations, speaking languages closely related to German (Yiddish, German Romani), be considered German?

How can you interpret those laws as being about anything but racial categorization - unless you have an agenda to sidestep and downplay the fact the Nazis repressed and murdered people whom they saw as not being part of their own presumed "race".

The point I was making above was that Nazis were concerned about German-ness (well, Aryan-ness) not whiteness. Classifying them as white supremacists is generally incorrect.

The problem with that argument is that the Nazis considered the German "race" to be the paragon of "whiteness", and other less-German white peoples, like European Jews, to be degraded. They absolutely conflated "whiteness" with their idealized German identity.

There is also historical conflicts between ethnic Germans and other ethnic groups. The Nazi's had a plan to exterminate most Slavs which includes Poles, Russians and Ukrainians after they won the war.

See Generalplan Ost.

Slavs were explicitly not German according to the Nazi's definition. However, they were interested in re-absorbing ethnic Germans from Slavic territories.