Borders physically exist. There are police who will arrest or even shoot at those who cross them in the wrong way. “After a socialist revolution” is so vague as to be meaningless. Yeah, if you establish Utopia tomorrow there will be no borders. Can we get back to talking about the real world?

borders objectively exist. saying “it’s good for people over that border to organize” is sensible for those in touch with objective material conditions

It’s not a shit title. If you go outside and talk to people, they generally can understand that “American socialism” is equivalent to “socialism in America”.