The French wars of decolonization were wars of a particular kind: they were not recognized as wars at the time, lasted longer than most wars, and erupted far from the metropole; they nevertheless had significant impact on metropolitan France. For these reasons, they generated anxiety in the army as well as among the civilian populations at home and overseas, giving way to political unrest and a radicalization of positions, particularly on the far right. This article follows the development of a veterans’ association: the Association of the Combatants of the French Union (ACUF), tracing its transformation from a charitable society to a paramilitary organization. Initially focused on assisting wounded veterans, welcoming back soldiers who were repatriated from the colonies, and honoring the dead, the association gradually engaged in a process of radicalization that eventually landed its leaders before the Court of State Security in 1963 for offenses against national territorial integrity. Indeed, the ACUF became a subdivision of the OAS [Organisation de l’Armée secrète]. More specifically, the article follows the personal trajectory of Louis Thomas, the president of the Lyon branch of the ACUF, whose story shows how an ordinary man passed through successive thresholds of violence, from hurling invectives to (alleged) terrorist attacks by way of sabotaging political meetings, engaging in street fights, and finally, murdering an Algerian. Based on numerous archival source related to police intelligence services; military justice; and militant national and regional presses as well as oral interviews conducted by the author, this article uncovers the interrelated dynamics between a personal life and militant associations in the context of acute political crisis whose stakeholders included political and military authorities and the media. This account is a deep dive into the Algerian war of independence, offering insight into its impact on everyday life.