A lot of food for thought all around.
Edit since I am throttled on posts and cannot reply below: The US briefly blockaded Cuba in the 60s, but they have only embargoed them since then. They are not blocked from international trade by the US, except with the US. There is no meaningful block from Cuba engaging in the greater international non-US "global economy" such as EU,Asia, etc.
What are you talking about?
And then reinstated in 2017. How has that been "over for a long while"?
For instance, I can buy Malibu rum, no matter that Pernod Ricard does business with Cuba. Or flights in USA with Air France, no matter that they also do business in Havana. Or ZTE phones which are imported into both USA and Cuba from China (carrier limitations but only because USA government won't do business with ZTE associated businesses, not because they can't be sold in USA). Or Sinopec (oil) which does business in USA including a large investment of presence in Texas but also does business with Cuba.
Yes your blanket any is a lot more applicable if you said the truth which is any business that wants to do business with USA federal government which is much closer to the truth (but even then, Sinopec for instance has through its subsidiaries been allowed to bid on strategic oil reserve transactions no matter their ownership is a major trader with Cuba).
Cuba is actively trading with EU, Asian, etc companies that are also trading with USA.
Air Canada flies to the US and flies to Cuba:
It’s pretty hard to sort out after the fact.
Once upon a time, there was COMECON, a huge bloc of socialist countries trading with one another, whose intent was precisely to limit Western pressures. It included some fairly developed countries like Czechoslovakia and GDR. 500 million people in total, similar to the US and Western Europe together back then. A huge market in total, from Leipzig to Vladivostok to Saigon (after it fell).
(BTW Cuba was a member of COMECON and it was a very non-productive member, being heavily subsidised by the Soviet Union all the time. I still remember the Cuban oranges sold in Czechoslovak shops, which were so full of stones/seeds that they were barely edible. No one would voluntarily buy them unless there was no alternative available, but there usually wasn't one. A good metafor for what was going on.)
They still ran their economies into the ground because Marxist-Leninist economy doesn't work in practice. Marxism as a theory is catnip for intellectuals, but neither Marx nor Lenin ever tried to run a corner shop, much less an actual factory. The resulting misalignment of interests throws off almost everybody and a country practicing Marxist-Leninist approaches to economy will end up with just two really functional institutions: the secret police, to keep the comrades in power, and the (very non-Marxist) black market, which is tolerated because otherwise the population would starve. If it is not tolerated, the population will starve, but only a few countries like North Korea were crazy enough to go down that road.
The same happened all over again pretty much everywhere where it has been tried. China only started to economically grow after ditching Marxist economy for market reforms in 1979. India was never totalitarian, but toyed with Marxist approaches until 1991, when the "License Raj" was reformed; since then, it has been following Chinese economic growth along a very similar line.
Heck, even very early idealistic Israel ran into somewhat similar problems, although all the kibbutzniks were there voluntarily and eschewed use of state violence to build their utopias.
In materialist philosophy, the real world exists entirely outside the mind and the mind only interprets it. Having dialectical materialism would imply that material reality has a final destination (=communism) that it is striving to achieve and that rather than concepts such as life and death contradicting each other, it's people that are contradicting each other (capitalists vs proletariat). Because forward progress is guaranteed, there is no need to have knowledge/discussions about how to arrive at the final destination. The best way to accelerate the process is to simply destroy the existing order no matter what it is. Reformists (people who demand incremental improvements) are slowing down progress toward utopia while supporting the status quo and should be held in contempt.
What this ultimately means is that Marxist socialism has never been about building a good society for people to live in, but to dismantle the status quo, no matter what it is. This makes Marxist socialism an extremely attractive ideology for ruthless, violent or narcissistic individuals, while simultaneously luring in unsuspecting people who just want a better life and have reasonable grievances with the status quo. These subtractive ideologies fail because they're biting the hand that feeds them.
There is this socialist streamer (Vaush) that summarized all of this in a single sentence. "I don't care about principles, I only care about winning."
That's the thing about change. It gives the lie to cliché