“Rambam writes that we have an obligation to force the nations to follow the 7 mitzvos of Bnei Noach.”
This would require repealing the First Amendment to the US Constitution along with similar provisions in every state Constitution.
It would require reinstating the sodomy laws, which would require yet another amendment to the US Constitution reversing the doctrine of substantive due process.
It would require changes to death penalty prosecutions to require
eyewitness testimony.
It might, depending on which posek you hold by, require the banning of Christianity as being a form of idol worship. (Islam, however, would be permitted.)