Still in its infancy, the new year has already spawned a theme: diversity. Is it possible? Is it desirable? Is there any common ground, besides mutual, irreconcilable loathing, between those who declare "I am Charlie" and those who riposte "I am Mohammad"?

The West extols freedom; Muslims rally round the Prophet. Demonstrations worldwide, on both sides of the cultural rift, draw tens of thousands, hundreds of thousands, millions. "Insulting the prophet," said a demonstrator in Amman, "is terrorism." If that's true — if offensiveness is an act of terrorism — given the elasticity of the word "offensiveness," we are all terrorists. Everyone is somebody's Charlie.

We take the world's temperature as the year dawns, and find it feverish. The bearers of contagion are those who are not us — whoever "us" is. Writing in Sapio magazine, Jean-Marie Le Pen, godfather of France's resurgent political right, warned Japan not to make France's mistake with respect to immigrants. The mistake was to welcome them. The price, in his view, is the choking of the French nation, culture and economy by unassimilable immigrants and their scarcely less unassimilable, so it seems, French-born offspring. "Ultimately," Le Pen fears, "it will come to Muslim immigrants cooperating with terrorists who carry out massacres."