I take your point about companies like Medium being strictly American, but as a writer, I have freelanced as a writer for companies in other countries while living in Spain and the UK, and I never had any withholding tax. I think you are mistaken, but I'm willing to be proven wrong if you give me the exact legal wording that says so.

As I lived in the States for 11 years, and as I have a social security number, something may be possible if I can, indeed, reclaim it.

I would like to see that legislation. Thank you.