The end of the Second World War and the establishment of the UN have provoked new changes as regards international relations. Not only has decolonization became one of the most fundamental rhetorical objectives of international society, but also entrenched changes towards the composition of this society (a majority of underdeveloped countries in the UN system). As a consequence, it seemed that international society and international law would propitiate a new era of mutual development. Nonetheless, new discords have erupted in international society, mainly as concerns the economic realm. The main objective of this article is the demonstration of the continued use of international law (its content and sources) as a legitimizing aspect of global powers imperialism over peripherical States of the world, primarily since the Pax Americana (neoliberal hegemony). To achieve this crucial goal, Critical Theory and International Political Economy’s (IPE) methodologies will be essential, as well as the intrinsic relation between International Law and International Relations’ scopes of knowledge. The utmost result of this research highlights neo-colonial policies in DI’s background. Keywords: Neocolonialism; Neoliberalism; International Law; Hegemony; International Economic Governance