Examination of the current regime’s potential also reveals its limitations in terms of the need to correct the asymmetry of the IIA regime and reflect the interests of the victims. On this basis, this chapter examines how the analysis presented in this study may inform discussions about the reform of the IIA regime. To incorporate the interests of victims in the dispute settlement mechanism, it specifically proposes a mechanism for encouraging third parties’ participation in investor–state mediation. This study concludes with the argument that the IIA regime should not provide an opportunity to benefit from the existing gap between investment protection and the lack of effective regulation of TNCs’ conduct; rather, it should operate as a mechanism that protects and advances responsible investment. Fully utilising the potential of the current IIA-based dispute settlement mechanisms to materialise investor responsibility has a broader impact than achieving fairness in specific disputes and will serve the objective of advancing sustainable development.