So? The belief is the cornerstone of their culture and being. It’s as important as any actual, factual historical event to them.
First off, I’m not claiming that anyone doesn’t, or ought not to, have the right to print those cartoons. I’m saying that they ought not to have printed them anyway. I’m not saying anyone has any special rights.
Christians have the same rights to be offended as anyone else.
The reason they haven’t been so offended has something to do with the differences between the religions (you can draw Christ), but mostly it has to do with the context of the mockery. Most anti-Christian ridicule comes from within the Christian culture, from a minority position. Christians, although some bitch and moan otherwise, know that they’re religion and values are safe and aren’t really under attack.
Muslims, on the other hand, are being insulted by a more powerful exterior force. It wasn’t that long ago that European powers controlled Muslim lands outright, and the West still meddles in that area.
Basically, it’s the same reason that Black people can call each other “nigger”, but a White person should be careful with that word.
Freedom
Democracy
Women’s Rights
Capitalism
Secularism
And a big heaping helping of Western culture on the side.
These are values, Western values, that Europe and the United States is attempting to make the world adopt. Pretty much by gunpoint in the case of Iraq. The fact that these are good values, values that we may agree that they should adopt doesn’t change the fact that the West is seeking to alter the culture and makeup of the Muslim World. This fact makes insults more pointed. And the insults make the work of changing Muslim culture for the better more difficult.