In practice, the key ways that the US exerts influence outside of its own borders: (1) Sanction the company, which means any other company that does business with that company can also be sanctioned. (2) If enough companies are evading sanctions in a single country or the govt is helping those companies, then threaten to cut the country from USD settlement with the Federal Reserve, e.g., no USD FX allowed. That pretty much screws most economies. The "long arm" of the US govt is very, very, very long!

To be clear: I am not saying any of this is fair (or legal); I am only explaining how it works.