When the benefits of creating a new country outweigh the costs (to shareholders), does it fall within the fiduciary duty of corporate leaders to form a new country?
I wouldn't be surprised if you only needed one country to do it and then could funnel all your taxes through that complicit country. If that happened we would be back at the double Irish with an extra step. Forcing all participants to recognize the same countries could have all kinds of good or bad side effects especially when you consider China and Taiwan.
Plenty of tiny nations already solved this problem by contracting other nations instead of building their own defense infrastructure. Granted it's not free either but much cheaper than building your own.
It's not my plan, nor am I advocating for it. I just think it's a potential in the logical progression of events.
To your point though, what if a few or even all Fortune n companies formed countries (or one country together). Who would the sanctions really hurt/benefit? I doubt it would hurt the corporate nation states as much as the others.
I doubt all fortune 500 companies would just accept losing access to the markets of 130 countries, so I'm guessing you're talking about tariffs rather than sanctions (which imply a total ban). In that case it would depend on how punitive the tariffs are. If they're not punitive enough then you're right, companies might just deal with the tariffs in which case the corporate tax gets turned into a tax (assuming mot of the countries are in on it. If it's punitive enough (ie. it's better to pay the local corporate tax than to pay the tariffs) then you'd expect competitors to break ranks to gain a competitive advantage.