Why has the Islamic Republic of Iran endured for almost three decades amidst recurring predictions of collapse? I argue that the post-revolutionary regime in Iran remained durable because its state-building project relied on welfare. The Islamic Republic, confronted by international isolation and an eight-year war, channeled the social mobilization it inherited from the 1979 Revolution into a set of institutions that promised welfare provision to marginalized social groups in exchange for warfare participation. This warfare-welfare complex established linkages between the state and a wide array of social groups inside Iran. The social embeddedness of the regime strengthened the capacity of the Islamic Republic to sustain serious challenges to its survival. These state-society linkages, however, constrained the state even as they increased its strength, and continue to shape the social and political trajectory of Iran to the present. Through archival research, interviews, and ethnographic observation in three cities of Iran, this project seeks to reject the common assumption that Iran's post-revolutionary regime is an ideologically rigid, anti-modern state, or a stagnant rent-seeking, absolutist state. Instead, I situate Iran within the frame of a developmental state that engages in routine and unexpected negotiation with various segments of its population in order to remain strong enough to pursue nationalist strategies abroad.