re: #11 Obdicut
The notion that multicultural entities weaken a nation rather than strengthen it is false.
What usually happens is you get a syncratic melting pot. Rome becoming Christian, Mithra worship, adoption of Greek philosophy, etc.
It actually strengthens a culture to be multicultural.
Usually the most vibrant culture is the one that is open to outside influence. The closed off cultures become dead ends.
Arab Islamic culture was at its height when it was open to being Hellenized (some scholars say Islam was Hellenized the way Rome was) , etc.
ENgland is cool now because it was open to outside influences the way the USA back in the 60s was not. The British invasion in music happened because British kids were exposed to a culture that was alien (American blues) when in the USA it was still taboo (the 50s wave of Rock&Roll had waned) and then we have hip hop, etc.