This chapter explores political developments in the Republic of Vietnam (RVN) from the coup against President Ngô Đình Diệm in November 1963 to the consolidation of General Nguyễn Văn Thiệu’s power as president in late 1968. The dominant feature of politics in the RVN during this time was the monopolization of political power by a divided military. But noncommunist civilian groups challenged military rule in the form of street protests, armed rebellion, and constitutional assemblies, forcing the military to accede to elections and the return to constitutional government in 1967. These changes created limited opportunities for competitive politics but also granted a veneer of legitimacy to military rule as Nguyễn Văn Thiệu won election and outmaneuvered his rivals within the armed forces. The chapter addresses the powerful influence that the United States, as well as historic faultlines in Vietnamese noncommunist nationalism such as religion, regionl and differing experiences of colonialism and communism, exercised on RVN politics. The chapter contends that the RVN was both an outpost of the American empire and a site of febrile postcolonial politics.