> Those statements are offered as truism ( and they do sound true enough ),but are they anything more than a hopeful assertion?

For the US / Euro, yeah you can just digitally wire say $ 150 million no problem. You just can't physically fly out with a suitcase of $100 bills.

This is not true for something like China [1].

The counter-topic is usually Labor. You very much cannot just go to the US and work but you could from China invest in a US company. So Capital knows no borders while Labor does.

[1]: https://www.tradecommissioner.gc.ca/china-chine/control-cont...