Complex sentence: National unity arguments are, for example, if immigrants isolate themselves in their own communities and refuse to learn the local language, this might eventually undermine the national unity, as well as the cultural and religious unity of a region or a country.
Split into simpler sentences: National unity arguments emphasise on language use and isolation: if immigrants isolate themselves in their own communities and refuse to learn the local language, this might eventually undermine regional and national unity. Unity arguments can also be extended to the cultural and religious unity of a region or a country.