I think Americans believe their country will last a thousand years.
I agree with you about the danger of the far right to Europe. We remember when they fascists held a grip over the continent during the last century and how it led to internecine deaths and horrors. The European Union was established to ensure that this does not happen again and it is working. No more are European Union countries solving differences with wars but instead debate in a parliament how best to cooperate for the common good. Nationalism which threatens a breakup from within would be a catastrophe.
You've got to love this method of argument -- "The EU is so great, now Trump is ruining it all!" If the EU was so great for the people in it, then why is there so much popularity in leaving it? Trump magically convinced them things are bad, when everything is good?
The "far right" is gaining popularity in Europe because of the failed open borders policy of the globalist left.
You put the words "The EU is so great, now Trump is ruining it all!" in quotation marks but no-one wrote that. You might be paraphrasing incorrectly. Your claim that there is widespread unpopularity of the European Union (EU) is untrue. There was a referendum in Britain and the electorate narrowly passed (52%) the proposition to leave the EU. No other country has applied to leave. Even in Britain, the majority in Scotland and North Ireland voted to remain. But Donald Trump has been praising the English for leaving and he is expressing his opinion that other member states should also leave. Now, honestly, how would Americans feel if the Chancellor of Germany said it would be good if Idaho were to secede from the USA? What a nerve that guy has.
Before the vote he did not condone or condemn Brexit, he just predicted it would pass. He also was not elected, he was a private citizen at that time. Comparing that to Merkel is disingenuous.
Obama was the one that threatened the U.K. by saying if they chose to leave, they would be at "the end of the line" for trade negotiations. Didn't hear any progressives complain about that, did we? No foaming at the mouth media stories about the US President "meddling" in UK's election/referendum.