What started as a trial against Geert Wilders for alleged Islamophobia has nearly turned into its opposite: a historical case about the message of the Quran. The Amsterdam court trying the controversial Dutch politician is now preoccupied with the question of whether this book, sacred to more than a billion believers, can be compared to one of the most vile publications in the history of Western civilization—Hitler's "Mein Kampf." What could possibly go wrong?

In his writing and speeches, Mr. Wilders has found these two works...