This chapter theorizes corporate social responsibility as the practical manifestation of the sustainable development principle of multistakeholderism. Corporate social responsibility enables discretion and is thus cognizant of the contextual challenges of businesses. However, this discretion is framed by sustainable development, so that any corporate social responsibility initiative is the result of a process whereby the corporation has integrated the three dimensions of sustainable development. In this way, a vertical rebalancing of international investment treaties is achieved, opening avenues to reflect on corporate subjectivity in international law more generally. At the same time, the inclusion of sustainable development in investment treaties addresses several aspects of horizontal rebalancing as an obligation shared by the home and the host State.