The lesson of the Muhammad cartoon controversy is: Multiculturalism between nations is inevitable, but multiculturalism within nations is disastrous. Protests, many of them violent, have erupted across the world - including Europe, Australia and New Zealand - after the appearance of cartoons depicting the Muslim prophet Muhammad in unflattering ways. It's time for all of us to recognize that different cultures have different values. For the West, broadly speaking, the highest value is freedom, including freedom of religious expression. But for the Muslim world, the highest value seems to be Islamic piety. To draw such a distinction between West and...