I’ve read that at least in the case of some EU banks, not following the foreign sanctions is quite literally not an option for them.
If you don’t follow sanctions, other banks either with branches doing business in the U.S., or their partner banks, will refuse to continue banking with you out of fear for not following sanctions – which include banks enabling sanction-circumvention. Essentially, even if the bank doesn’t want to deal with USD (which most banks would still like to do!), you’re still bound by the sanctions. A bank won’t survive long or well if it’s cut off from a majority of other banks.
This is just a case of carrot vs stick. European countries need to threaten their companies with an even bigger stick if they follow foreign sanctions.
China does this via laws that say, if you do not provide services to Chinese citizens/entities citing foreign sanctions, they can send you to a gulag forever. Seems to be fairly effective, considering how heavily sanctioned Huawei is.
Which is why it would need to be a law. The only option would be for the US to take the insane move of cutting off every bank in Europe. If they did actually do that, while it would be painful in the short term, it would be incredibly beneficial for Europe in the long term.
After the last 2 years you _still_ haven't learnt that _everything_ like this is completely negotiable and can change tomorrow? That it's all might makes right? God, you must've been one of those people who in 2014 claimed it was unthinkable that a country would leave the EU, or took Trump's threats as fact even after his 20th TACO turn.
All these hard "immediate consequences" scenarios are pure fiction. Not because they can't become truth, they can. But there's a hundred other possibilities. Literally sticking to the "letter of the law" is just one of them, and not a particularly likely one.
If you don’t follow sanctions, other banks either with branches doing business in the U.S., or their partner banks, will refuse to continue banking with you out of fear for not following sanctions – which include banks enabling sanction-circumvention. Essentially, even if the bank doesn’t want to deal with USD (which most banks would still like to do!), you’re still bound by the sanctions. A bank won’t survive long or well if it’s cut off from a majority of other banks.