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.