"one europe" except for all the other bits of europe
Indeed, except for the bits of Europe which chose not to be part of the main part of Europe. That's how it works.
And by "it" we mean both "free choice to be part of the union or not" and "legal jurisdictions".
Well, isn't it the same for America? America is more than the US. I know the name Americas is used, but that is more like an afterthought.