[jacobgkau]

> If I remember correctly, gaijin is just how you say 'foreigner' in standard Japanese.

I think this depends on tone. It is a literal translation, but I don't think you have to call someone non-human for it to be rude.

> I can imagine that people in, say, the United States wouldn't be very happy if I went around and only spoke Dutch.

We do have a large amount of people (and an increasing number of businesses) who think it's fine to only speak Spanish.