In Western discourse today the charge that Islam is “not just a religion” but a comprehensive social system is leveled to cast doubt over Muslims' ability to integrate into a political community. In the People's Republic of China, this understanding of Islam has served the opposite purpose. From the perspective of the Chinese Communist Party (CCP), religion cannot be the basis for legitimate political identity. Islam, however, is not just a religion. Rather, as a “social system,” Islam constitutes a legitimate basis for national identity, and the Hui (Huihui), or Chinese Muslims, therefore constitute a minority nationality. This essay explores the origins of the CCP's understanding of Islam in the 1930s and 1940s, when the Party first formulated its policy vis-à-vis the Hui. Glasserman shows how this understanding of Islam as “not just a religion” suited the political, geopolitical, and ideological circumstances of the Yan'an period (1936–48). He also shows how this understanding was informed by contemporary Hui discourse and activism.