It goes into public domain in the US in this case. In other countries it may remain copyrighted or already have been in public domain, depending on local laws.

It goes into public domain in the US in this case. In other countries it may remain copyrighted or already have been in public domain, depending on local laws. In general, countries can't/don't enforce their laws outside of their territories, with lots of nuance and boundry cases. There is zero chance that someone would "go after you" for, say, buying a copy of a Tintin book that was made without permission, in America. If you, say, wanted to publish a Tintin book and then export it to Europe, they might disallow it.