This chapter explores the application of economic theory regarding vertical integration to the analysis of reshoring critical minerals supply chains. Drawing on extensive economic literature, it builds upon policymakers' security and sustainability considerations by incorporating an understanding of the economic forces underpinning vertical integration. This includes the literature on transaction costs (Coase, 1937; Williamson, 1975, 1985, 1992)—complemented by the property rights framework (Grossman and Hart, 1986; Hart, 1989; Hart and Moore, 1990)—and imperfect competition (Perry, 1989). By adding considerations of vertical integration—mitigating the potential for hold-up and underinvestment, and imperfect competition—to the standard considerations of the supply security and sustainable production practices, we propose a conceptual framework for policymakers assessing the benefits and costs of reshoring strategies.