Multiculturalism is the proposition that all cultures are equal, that no single culture is superior to another. It is premised on the observation that all cultures are traveling along their own historical timeline, so all have the same claim to existence.
In the context of multiculturalism, imperialism is a sin, perhaps the original sin, as imperialism is the inverse of multiculturalism. If no culture is superior, no culture has a right to assert dominance, thus there can be no argument in support of imperialism.
Multiculturalism claims the mantle of moral superiority in light of its acceptance of all cultures. Energized and validated by this assumption of morality multiculturalism spreads across the world.
Lost is the fact that multiculturalism itself is a culture. By asserting itself as superior, multiculturalism is in fact an imperial force. Even more damning, multiculturalism desires to impose itself over all other cultures, effectively behaving as an arch or omni imperialism. Rather than accepting all cultures, multiculturalism seeks to subvert all under one – its own.