>You cannot make blank statements about the US on a platform that has an international audience.
I'm not sure what you're saying - I was very clear that this is US specific law.
That being said, while I don't exactly know how it works for works created by Berne signatory country citizens, I suspect foreigners still have to register in the US before suing in the US. "International copyright law" is generally just a pinky promise to let foreigners use the copyright system as it exists in other countries, so the rules you have to follow depend on what forum you sue in. For example, if you can get standing to file a copyright lawsuit in Japanese court, then your defendant can't mount a fair use defense, because there is no fair use there[0].
That being said, I do have to wonder if you could get SCOTUS to agree to "foreigners don't need to register but Americans do", because that's the sort of blatantly stupid ruling that only a law-huffer would love.
[0] To be clear, fair use is generally a concept borne of the Anglosphere and it's weird obsession with common law and precedent. Other countries don't have it. But those countries will still codify exceptions to copyright that do similar things. Japan is just unique in that they didn't even bother doing that, so it's illegal to, say, review anime if any Japanese fans might be watching your reviews.
