Historically, Multiculturalism always produced conflict for Dominance between competing Cultures

There's a reason why the Presidential Seal has the Eagle holding both the Olive Branch of Peace AND the Arrows of War.

Historically, Multiculturalism always produced conflict for Dominance between competing Cultures which is why Assimilation & protection for Dominate Language & Culture with minority populations protections from discriminations was preferred.

All the great empires were cobbled together from different peoples, including the two oldest countries today, China and Iran. Rome was so mixed, nobody's even sure what its original roots were, whether they were lost leftover Hittites, or gang of thieves from India, or just an offshoot of Etruscans and other local people.

They never learn, do they?