You are obviously trolling, but I'll answer you anyway. Nationalism (especially in the US where the two overlap much less than in other places) refers to citizenship rather than ethnicity. Nobody is suggesting deporting US-born ethnic Africans.
So why have borders? It's so you can have programs that help the local poor. Any kind of welfare/medicine/UBI type program has to have some kind of filter on it or the poor of six continents would sign up and bankrupt the programs, so that filter is citizenship. The same applies to local wages. Allow local companies to hire foreign workers and wages equalize, which for US workers means they go down. And the culture of the US depends on having a middle class.
> What is the national culture of America?
Are you honestly asserting that it doesn't have one? The culture in Silicon Valley is exactly the same as the one in Beijing? The one in Alabama is identical to Russia?
https://www.youtube.com/watch?v=SGJ5cZnoodY
> The one in Alabama is identical to Russia?
https://www.snopes.com/fact-check/russian-than-democrat-shir...
First, the Soviet Union had just become best buddies with the Nazis (Molotov-Ribbentrop Pact and its secret addendum). Second, after demands to cede Finnish territory were rejected, Soviet Union staged a false flag attack and threw eventually overall about a million troops at Finland. The attack was repelled but Finland had to cede roughly 12% of its territory.
Third, the Soviet Union was clearly not done, so what could Finland do? The horrors of 1939 were bound to happen again; Soviets were gearing for war and one could not really expect the weak and submissive Soviet population to make any kind of change for the better within their nation, that much had been taken care of by the death camps, deportations the secret police, tight control of the media, etc. The only actor who could realistically provide substantial help against the inevitable rematch with the Soviet madman was Nazi Germany, a nation run by another madman.
Had USA, UK and the Allies sent troops or at least enough material, or pressured the Soviets to drop their ambitions of annexing a neutral country, Finland would not have needed any help from the Nazis. As it was, Allied help on a meaningful level did not happen. The neighbouring neutral Sweden helped the most, for obvious reasons: if Finland fell, they would be next.
So, yes, it was an existential threat. However, as crude as it may sound, given the circumstances, Hitler being evil or not was surely not even considered.
There is good reason to believe that the Finns aligned with Nazi Germany for purely tactical reasons of survival rather than any shred of ideological agreement. The notorious Hitler-Mannerheim conversation which consists of fifteen minutes of tape-recorded conversation was recorded initially without der Fuhrer's knowledge or consent, an act of subversion, and was preserved rather than destroyed, again against Hitler's express orders. It is essentially a boastful and deluded monologue from Hitler to an audience that continues to humor him rather than engage with him, even as he escalates into evident delusion and falsehood.
https://en.wikipedia.org/wiki/Hitler_and_Mannerheim_recordin...
Mexico and Texas, which are pretty culturally similar and until recently were the same country
Actually, Texas was part of independent Mexico for less than 15 years, and that ended 182 years ago.The most notable is our very expansive definition of free speech, which has broad popular support and is found almost nowhere else in the world. American culture also exhibits a relatively high support for economic freedom and avoiding government largesse. Additionally, we have a strong liking of suburbs (as typified by the proverbial "white picket fence").