I’m pretty sure Ireland is where all the major companies are “headquartered” and technically keep all their money there for tax reasons. Ireland could just freeze the bank accounts of Apple, Google, Microsoft, Meta, Intel, … Or do something similar if they so choose as retaliation. Would be devastating financially afterwards, but would get the US’s full attention

I’m no authority on anything involved in such an idea, but I just can’t imagine how the economics of a vacuum tunnel could be viable. The maintenance costs on constantly running lots of industrial scale vacuums sounds crazy expensive. I hate trying to keep good suction out my vacuum cleaner and imagine at huge scales things get harder, not easier. Maybe there are clever people who have a solution for that and it’s not a big deal though. No clue.