There are strange happenings in the world of international jurisprudence that do not bode well for the future of free speech. In an unprecedented case, a Jordanian court is prosecuting 12 Europeans in an extraterritorial attempt to silence the debate on radical Islam.

The prosecutor general in Amman charged the 12 with blasphemy, demeaning Islam and Muslim feelings, and slandering and insulting the prophet Muhammad in violation of the Jordanian Penal Code. The charges are especially unusual because the alleged violations were...