The "Long '68" period is characterized by a potent re-emergence of minority nationalisms, protest regionalisms, and Indigenous ambitions in the West,from Brittany to Quebec, passing through Catalonia,Wales, Australia, and New Zealand.This book reviews some of the most representative cases as well as lesser-known examples, attending to the chronology, causes and consequences of this period's nationalist renewal. This collection of essays is the first to propose a global and comparative view of this "national wave" in an attempt to understand the simultaneousness of these movements .Several hypotheses are put forward. The profound sociocultural changes caused by the socioeconomic "Golden age" of the 1950s and 1960s forced social groups and individuals to call into question their worldview, as the culture they inherited grew increasingly distant from reality. Moreover, the internal influence of the decolonizing and anti-imperialist struggles weakened the nation-state and offered regionalist militants a new discursive repertoire. Finally, the social struggles of the New Left and the generalised spirit of protest of the 1960s-70s -which reached their zenith in 1968 - had a cognitive impact that paved the way to an ideological transformation unlike any seen before.This book offers a historiographic analysis of the "Long 1968" period in its many dimensions (political, socioeconomic, cultural) as well as a theoretical and sociological reflection on the dynamics and shades of its nationalist and regionalist claims. It is the first comparative study of international scope to shed light on the simultaneous re-emergence of claims of a nationalist nature among minorities in this decade of protest and utopia.This book is published in French.-Les " annees 1968 " se caracterisent par une forte resurgence des nationalismes minoritaires, des regionalismes protestataires et des aspirations autochtones dans le monde occidental - de la Bretagne au Quebec en passant par la Catalogne, le Pays de Galles, l'Australie et la Nouvelle-Zelande.Cet ouvrage passe en revue des cas parmi les plus representatifs ainsi que des exemples moins connus, s'attardant a la chronologie, aux causes et aux consequences du renouveau nationaliste de la periode. Cette collection d'essais s'inscrit dans un horizon international et les cas abordes permettent, a partir du particulier, d'eclairer la dynamique globale a l'oeuvre. Plusieurs hypotheses y sont avancees. Les profonds changements socioculturels provoques par les Trente Glorieuses obligent les groupes sociaux et les individus a reinterroger leur environnement des lors qu'ils quittent la reproduction de l'existant. De plus, l'influence interne des luttes decolonisatrices et anti-imperialistes fragilise l'Etat-nation et offre un nouveau repertoire discursif. Enfin, l'impact cognitif des luttes sociales des annees 1960-1970 autour de la " nouvelle gauche " et de l'esprit contestataire, symbolise par l'annee 1968, prepare la voie a une transformation ideologique sans precedent.Ce livre propose une analyse historiographique des " annees 1968 " dans toutes leurs dimensions (politique, socio-economique, culturelle), en meme temps qu'une reflexion theorique et sociologique sur la dynamique et la coloration des revendications nationalistes et regionalistes.Voici la premiere etude comparative d'envergure internationale a jeter un eclairage sur la simultaneite de ces resurgences revendicatrices a caractere nationalitaire.Ce livre est publie en francais.