Chapter 6 investigates the political contestations over US sister-state agreements with Taiwan Province. It argues that the ROC authorities deployed Taiwan’s provincial government to formalize relations with US states. The chapter examines the resulting political contests involving US state leaders and agencies. It also analyses the roles played by external actors (including the State Department and PRC/ROC provincial and central governmental officials), who debated subnational authority to formalize relations with Taiwan, while weighing the related economic costs and benefits. It ends by noting that these intra-subnational conflicts resulted in states articulating their own China policies and related constructions of Chinese sovereignty, sometimes in open defiance of the Washington and Beijing-stipulated One China policy. The chapter features two major case studies: Minnesota’s debates on its sisterhood relationship with Taiwan and Oregon Governor Atiyeh’s efforts to craft a China/Taiwan policy that allowed his state to maintain cordial relations with both adversaries (‘Atiyeh formula’).