Multicultural versus monocultural societies and countries

[Viking]

Continuing the debate that I initiated here.

My claim: a world where all the countries are largely or completely monocultural is vastly preferable to a world where X number of countries are solidly multicultural.

That's what I've been trying to say.

I don't think labeling multiculturalism as "one more headache [...] that the country in question has to learn to deal with" does it justice, though.

For me, it's like building a house in valley where it floods every year versus building it in a valley where it floods every 300 years. I view the facilitation of large-scale multiculturalism as ultimately irresponsible.

Id argue they are both vulnerable to "nasty things" but in different ways.

Multiculturalism never prevented the USSR's imperialistic ambitions, neither does it prevent Russia's imperialistic ambitions now. It did not prevent the Holodomor, it did not prevent the USSR from ethnic cleansing (like the Crimean Tatars). Who was in charge of the USSR when the two previous examples took place? Josepth Stalin aka Ioseb Jughashvili, an ethnic Georgian ruling from a mostly ethnically Russian city.

What nasty stuff happening in mostly monocultural countries happen considerably less often or never at all in multicultural countries?

EDIT: For this post, monocultural ≠ culturally conservative. It's about the number of cultures within a geographic area.