> Are we actually being serious right now of America doing a conflict with Cuba?
Sadly, I think the answer is yes. Iran might put a brief damper / brake on the timeline but the current US administration seems intent on seizing the moment and pushing out the Castro government once and for all. It's "beef" that goes a long way back, if you look up the history of Cuba, even how Fidel Castro first came to power was under the banner of pushing out that era's US-backed administration. And Cuba had been a point of major US economic interests as well so the USA was not happy to see the rise of the Communists in their backyard.
EDIT: you mentioned you're a non-American and the Americans you talk to are all upset/disappointed. If you're European especially, the Americans you're most likely to interact with are well-educated and liberal. There are parts of the country that are firmly pro-Trump, where it's completely out of the norm to have liberal / European-style values.
> It's "beef" that goes a long way back, if you look up the history of Cuba [...] And Cuba had been a point of major US economic interests as well so the USA was not happy to see the rise of the Communists in their backyard.
This is Mark Rubio*, and only Rubio. This admin is all about letting the people who helped put it together each have their turn at using the US as the vehicle for their personal grievances and profits. No part of this admin cares about the United States of America or its history. It's simply a tool for them, they won't have to deal with the fallout from trading it in for generational wealth that puts them above it.
*The NYT has many pieces on this