Resumen: This article reconstructs the early storage and use of chemical agents (chloropicrin, phosgene and ustard gas) by the French army in Morocco’s Rif War (1921–1927). Hitherto, most historiography about the French involvement in this conflict basically has omitted or denied the question of gas use, though in recent years there have been more nuanced approaches which have either admitted it or documented the intention of using that weapon. This research shows how the beginnings of French chemical warfare in Morocco took place in the context of the Riffian offensive of April–July 1925 against the line of advanced outposts north of Fez. The army first used chloropicrin gas that may have been stored in Morocco since late 1918, a moment in which parallel insurrections in the northern (Rif) and south-eastern (Tafilalet) regions of the Protectorate seriously threatened French rule. Later, after repeated demands by the High Commissioner, Marshall Hubert Lyautey, the French metropolitan government dispatched 10,000 shells loaded with phosgene and mustard gas from the World War I stock, which were shipped from Marseille to Kenitra and stored near the front. Documentary evidence to support these findings has been gathered from French, British and international organizations’ archives, as well as US, French and British newspapers. This pathbreaking investigation adds to the factual history about the frequency of gas use as well as to the historical debate about the efficacy of the 1925 Geneva Gas Protocol to prohibit the use of chemical weapons. Idioma: Inglés DOI: 10.3389/fpos.2025.1634144 Año: 2025 Publicado en: Frontiers in Political Science 7 (2025), [12 pp.] ISSN: 2673-3145 Financiación: info:eu-repo/grantAgreement/ES/MCINN/PID2024-156353NB-I00 Tipo y forma: Artículo (Versión definitiva) Área (Departamento): Área Historia de la Ciencia (Dpto. Ciencias Doc. Hª Ciencia)