Sure you can. We just don't. If you think the EU and the US couldn't get an international tax harmonization treaty that allowed countries to follow revenue into specified haven countries and tax the cash flows where the revenues were generated, you're nuts.

Viewed as distinct, large nations have a fuckton more negotiating leverage than Vanuatu's financial industry.

The real issue is that Vanuatu and other similarly placed tax havens aren't distinct. They are run by sophisticated professionals for capital holders in developed countries.

Those are the same people who are at the bargaining table; those who know about the issue in depth or that have substantial capital involved all benefit from the wealth extraction the current international regime provides.

Interesting.