This article argues, from the perspective of third-world approaches to international law (TWAIL), that the limitations of the Guiding Principles on Shared Responsibility (hereinafter ‘Guiding Principles’) stem from the very fact that their drafters did not contest the Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA). Therefore, before advancing a critique of the Guiding Principles, this article questions certain aspects of ARSIWA. It argues that ARSIWA tends to overlook the distinction between primary and secondary rules; does not take into account the thick and structured relations between corporations and the state in formulating the rule on attribution; completely neglects the principle of special and differential treatment (SDT) in framing secondary rules of state responsibility; and gives a negative connotation to the erga omnes principle. As a result, ARSIWA cannot do justice to weak states. Since the Guiding Principles merely seek to supplement ARSIWA, they fail to address key issues, including the shared responsibility of state and non-state actors, such as multinational corporations, for the violation of human rights and environmental norms and the application of SDT principles in determining shared responsibility.