Capo's right. The film-noir is a stylistic movement, no different from Italian neo-realism or the French New Wave. Like other respective movements, the film-noir is generally limited to one country, during one time-frame. The term film noir, meaning black film, was not coined until the movement was over halfway done. The high-point of the movement was after WWII was just finished, during the beginning of the cold-war and the genre represented the uncertainty of the United States and its future existence. Which is why there really is no such thing as "neo-noir," because they don't represent or depict the same things that traditional noirs do (and they usually aren't shot in black and white!).