Costa Rica is a foreign country, why should it not try to work round US laws? It has no responsibility to the US taxpayer or government. I don't understand how

Costa Rica is a foreign country, why should it not try to work round US laws? It has no responsibility to the US taxpayer or government. I don't understand how the US legal system has an jurisdiction there at all. OK, I assume that they would be leant on and "persuaded" to give this thing up, but that just big bully boy tactics. Not a moral or legal thing.