New York Times columnist Paul Krugman is back from his week off. Did he use this time to formulate his much-anticipated plan to save Social Security? Well, the changed numbers in the banner atop this page should answer that question. No, instead Krugman returns with vitriol and decides to compare his caricature of the "religious right" with Islamic extremists in Europe.

Democratic societies have a hard time dealing with extremists in their midst. The desire to show respect for other people's beliefs all too easily turns into denial: nobody wants to talk about the threat posed by those whose beliefs include contempt for democracy itself.

We can see this failing clearly in other countries. In the Netherlands, for example, a culture of tolerance led the nation to ignore the growing influence of Islamic extremists until they turned murderous.

But it's also true of the United States, where dangerous extremists belong to the majority religion and the majority ethnic group, and wield great political influence.

A Islamic gang conspired to murder Dutch filmmaker Theo Van Gogh for his movie "Submission" exposing the treatment of women in Islam. A Dutch member of parliament moves from safe house to safe house due to threats from Islamic radicals.

So, Paul Krugman compares these terrorist attacks designed to stifle criticism of Islam with peaceful protests and civil disobedience designed to save a woman's life.

I suppose it could've been worse -- Krugman could've compared Christians to Nazis.