In the late 20th Century, many commentators assumed that communism and autocracy in general were destined to fade away as the citizens of developing countries became increasingly prosperous and educated and gradually came to accept liberal democracy as the eventual form of government. However, recent democratic backsliding globally has generated interest in analyzing the persistence of authoritarianism in some states. Commentators have also begun to try to identify factors influencing these regimes’ form and longevity. In this paper, I analyze and compare the historical, cultural, and institutional factors which have shaped the Vietnamese and Cambodian communist regimes into the present day, with particular attention to state-society relations and the various ways in which the regime has sought to supplant and/or co-opt existing social and cultural institutions. I argue that the ideological co-optation of institutions has been much more complete and longer lasting in Vietnam.