The defendant in this case, Prof. Joseph Weiler, Editor-in-Chief of the European Journal of International Law, has a blog post in EJIL Blog on the progress in the case. There's a lot of interesting stuff there (including the phrase "libel tourism"), but especially fascinating is this backstory about how the case landed in a French court:
... Why Paris you might ask? Indeed. The author of the book was an Israeli academic. The book was in English. The publisher was Dutch. The reviewer was a distinguished German professor. The review was published on a New York website.
Beyond doubt, once a text or image go online, they become available worldwide, including France. But should that alone give jurisdiction to French courts in circumstances such as this? Does the fact that the author of the book, it turned out, retained her French nationality before going to live and work in Israel make a difference? Libel tourism – libel terrorism to some — is typically associated with London, where notorious high legal fees and punitive damages coerce many to throw in the towel even before going to trial. Paris, as we would expect, is more egalitarian and less materialist. It is very plaintiff friendly.
In France an attack on one’s honor is taken as seriously as a bodily attack. Substantively, if someone is defamed, the bad faith of the defamer is presumed just as in our system, if someone slaps you in the face, it will be assumed that he intended to do so. Procedurally it is open to anyone who feels defamed, to avoid the costly civil route, and simply lodge a criminal complaint. At this point the machinery of the State swings into action. [...]