Until now, it was generally understood that when an author exercises their termination right under US law, this applies only to US rights – international rights remain with the assignee (i.e., the publisher who bought the rights). However, a recent ruling by the US District Court for the Middle District of Louisiana upended this: The court concluded that a termination under US law applies globally – or, at least, in all the countries that participate in the Berne Convention.
Source: US court says copyright termination applies globally, potentially causing ‘chaos’ for rightsholders