The complicated relationship between France and Britain during and after the First World War in the Middle East manifested itself in paradoxical ways on the local level. Using English, French, and Arabic primary sources, this paper examines Anglo-French surveillance of Indian muslims and their waqf pious endowment property in the territory that became the French Mandate of Syria. The status of Indian Muslims and their waqf highlighted the confluence of Anglo-French anxieties regarding their Muslim subjects, as well as more prosaic concerns about migration and movement in the interwar Middle East. The goal of this paper is to demonstrate that the intelligence services and the administrative bureaucracy in the Mandate both conducted surveillance and their focus was not limited to policing political subversion or stifling nationalist opposition. Rather, the surveillance apparatus was sensitive to any potential source of instability, such as popular frustrations over stewardship of waqf. Surveillance of Indian Muslims and their waqf properties by British and subsequently French intelligence services in Syria helped define who was and was not Syrian and what was “national” versus “foreign” in the ambiguous context of sovereignty under the Mandate system. As “others within” the French Mandate for Syria, Indian Muslims failed to conform to arbitrary French administrative categories. The quixotic status of Indian Muslims long resident in Syria made them and their pious endowments perennial subjects for surveillance by the Sûrté and the Franco-Syrian administrative staff of the Contrôle Général des Wakfs. The case this paper examines underscores how seemingly monolithic ethnic, religious, and national categories were in fact highly fluid and mutually destabilizing in the period following WWI and points to the quiet role that intelligence services and surveillance work had in defining them.