That multiculturalism is superior to monoculturalism

Monoculturalism:"A single,homogeneous culture without diversity or dissension.(1)"

Multiculturalism:"Of, relating to, or constituting several cultural or ethnic groups within a society(2)"

Superior:"Higher in rank,status, or quality(3)"

(1)http://www.thefreedictionary.com/monoculturalism

(2)http://www.oxforddictionaries.com/us/definition/american_english/multicultural

(3)http://www.oxforddictionaries.com/definition/english/superior

"I think a multicultural society is much better because it allows more
freedom. People are freer to pursue happiness and do what they want.
People have more religious and political freedom. People in
multicultural societies are free to do whatever they want because no one
is allowed to force their beliefs on other people."

I think it is most important for me to understand my opponent's premises before I bring up my arguments for "monoculturalism." There seems to be a bit of confusion on the part of my opponent. My opponent has mistaken multiculturalism for liberal democracy. The former Soviet Union, modern Russia and China are multicultural. I would ask my opponent are they free countries? Or perhaps in the Soviet case, was it a free country(since it collapsed)? The former Soviet Union made up over a hundred different ethnic groups(1). I thought the Soviet Union was a totalitarian regime that tried to suppress religion and political freedom. Is this not true? Once, my opponent explains what she is associating with multiculturalism, we can move on in this debate.

(1)Sakwa, Richard (1998). Soviet Politics in Perspective. London: Routledge. pp. 242–250.