Separated from the European continent by a narrow strait, Tunisia has long been at the crossroads of various cultures. The decline of colonialism significantly influenced the formation of the Tunisian nation. This work explores the search for group identity among the local Muslims, Jews, and French, the conflicts surrounding national belonging, and the delineation from the "Other." Central to this is the French naturalization policy during the interwar period, which allowed educated Tunisian Muslims and Jews to acquire French citizenship and led to intense debates among Muslims regarding their own identity. In a second part, the study examines how these different group identities evolved during the decolonization process, who ultimately identified as Tunisian, and who emigrated as foreigners to France, Italy, or Israel. The focus of the work is on the tension between whether the formation of the Tunisian nation was defined religiously through Islam or secularly through the Arabic language.