Some opponents of open borders have argued that for large rates of immigration, it is possible for immigrants to interact solely among themselves and hence avoid acquiring fluency in the language of the country they are now in. This is particularly the case if there is large-scale immigration from a single country and the immigrants from that country are clustered together in enclaves.

To the extent that the problem is genuine, a keyhole solution to it is to impose linguistic and cultural fluency requirements as a precondition for migration.