French nationalism has always been a double-edged sword, from its beginnings in the French Revolution through the two Napoleonic empires, Boulangism, the Dreyfus affair, the fascist groups of the 1930s, Marshal Petain's National Revolution during World War II, and its latest contemporary incarnation in Jean-Marie Le Pen's National Front.

The author distinguishes between an "open" nationalism, based on the revolutionary values of liberty and equality for all, and "closed" nationalism, which is xenophobic - and, more particularly, anti-semitic. The author pays particular attention to French "national socialism," which wanted to transcend the categories of left and right in order to unite workers and owners under the banner of a providential leader, but which inevitably scapegoated the Jews.