French security policy has posed a puzzle to many people outside France, including politicians and even defense specialists such as the author, who took time off from his administrative position in Whitehall in order to study French thinking about security in detail. As with many other studies, he takes as his point of departure the traumatic defeat of 1940 but argues that the origins of current French policy are grounded in events and ideas that go back hundreds of years. They are ideas that are scarcely known or often misinterpreted in the Anglo-Saxon world.