Our Constitution is one of our greatest assets in the fight against terrorism. A free-flowing marketplace of ideas, protected by the First Amendment, enables the ideals of democracy to defeat the totalitarian vision of al Qaeda and other terrorist organizations. That free marketplace faces a threat. Individuals with alleged connections to terrorist activity are filing libel suits and winning judgments in foreign courts against American researchers who publish on these matters. These suits intimidate and even silence writers and publishers. Under American law, a libel plaintiff must prove that defamatory material is false. In England, the burden is reversed....Consequently, English...