Reckless speculation considering the latter did happen. You're fearmongering in order to drive censorship and oppression of viewpoints you disagree with.
Before Al Queda, the West's biggest fear was domestic white nationalist terrorists like Timothy McVeigh.
EDIT: It's very disturbing that so many people don't understand what the Nazi platform was all about. The supremacy of the "Aryan Race" was literally a platform of the Nazi party from the beginning. The subjugation of Jews was a part of the party platform from the beginning. The use of paramilitary squads to enforce ideological purity was a part of the party from the beginning. And it just got worse from there.
Furthermore, for a "white nationalist" movement they spent a whole lot of time killing and oppressing other "whites".
Fascists gained power in Italy, Germany, and Spain as a direct result of anti-communist sentiment (and in the case of Germany, a failed communist revolution). Mussolini's early writings were directly proposing nationalism as the answer to communism's failures. Everywhere fascism had success it was because it was pitted against the threat of communism. I don't know how the rise of Fascism was anything but reactionary.
But we're talking about the root causes of WWII. And one of the Nazi party's specific goals when invading Poland was to exterminate the Jews and Roma (Gypsy) populations of Europe.
Are you sure about that? Wasn't "the final solution" proposed significantly later?
It's also why it's not easily dispatched by enlightenment thinking... it survived those battles back in the 20th century and ultimately had to be put down with exercises of power (often military, sometimes social, rarely diplomatic).
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.
See Generalplan Ost.
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).
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 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".
Communism is problematic to them because it tries to eliminate social hierarchies deemphasizing national identity. Liberalism (in the classical sense) is problematic to them because of its (perceived) amoral decadence and its ability to empower "undesirable" "outsider" individuals to garner power inside a nation through wealth.
Islamic jihadis do control a few middle eastern nations. But they are quite powerless in front of the west. Even having access to natural resources like oil doesn’t protect the extremists (do I even need to give examples?). The most concerning Islamic state is Pakistan as it has nukes.
But if far right folks take over Austria or Germany again, or other European states or Russia or the US, they will control massive economies, WMDs and have the ability for complete domination in a way never seen before. Let’s just say it is better to be in control of any European nation as opposed to Libya, Syria, Iraq or Iran.
Are you saying that Islamic extremists took over most of the Middle East?