The Rome Statute is tied to territory, so any US citizens that find themselves in a country that has signed the Rome Statute can find themselves facing war crim

The Rome Statute is tied to territory, so any US citizens that find themselves in a country that has signed the Rome Statute can find themselves facing war crimes tribunals, hence the Hague invasion act. Even with that act in place there's a swath of western countries that former US statesmen like Cheney and Kissinger won't go anymore.