Perhaps "creation" was too strong a word. So no, it wasn't so much being imposed as it was a natural (albeit unfortunate) consequence of technology, which you point out, and post-war sentiment, which you also point out! I agree with you, I'm just saying it wasn't a good thing. When there's so few voices, there's only so much they can say.

> These earlier identities and divisions were eroding in favor of this shared one

Shared by white people, for the most part.

I'm not sure what you mean in your penultimate paragraph. "identities and divisions eroding" is only partly true, surely. You could certainly argue the opposite is true - see the women's lib and civil rights movements for examples of people fighting back against conformity.