Denmark, Canada, Panama, Mexico.

[Prairie Gates]

1. Most Austrians considered themselves part of a greater German "people" at the time

It was just a continuation of the unifications of the 1860s-1870s, which were not really that far off historically. Many of Hitler's annexations relied on the notion of ethnic Germans. Ethnic Germans in Austria, ethnic Germans in the Sudetenland, ethnic Germans in Silesia, in Danzig/Gdansk, etc., etc. Even ethnic Germans in Ukraine! Yes, tens of thousands of them. These were the claims.

So, that's what makes Trump's arguments very different. He frames it as pure geopolitics, resource extraction, and buffer zone security considerations - it's not so much 20th century biopolitics centered in ethnicity as it is some manner of neofeudalist imperialism. As he says about Greenland, he wants it because he wants it, and he's going to get it.

Nazi race-based imperialism was, shockingly, more subtle!