> US laws apply to US citizens and companies.
You're right. But trade in US Dollars with other countries need to go through US banks, which can be subject to prohibitions, which can be done by political motivation.
Also, the issue of the PetroDollar complicates things internationally as well. US throws a tantrum when small countries (or countries it can bully) trade Oil in other currencies. That is very important to keep themselves relevant and with some control over international trades.
Yet another aspect is that if any goods, regardless of who is selling it, contains more than 10% of components, technology, produced by a US company, such seller requires an US Export license to trade such goods with Cuba.
So it's not as simple as that.
https://shippingsolutionssoftware.com/blog/products-subject-...
Even more of a reason to detach from the dollar economy and New York centered digital transactions asap.