This dissertation problematizes the concept of power present in Michel Foucault`s philosophy in order to show its consequences for thinking the political in International Relations (IR) Theory. It seeks to deepen the dialogue with the critical perspectives that question the assumptions of realism since the 1980s. Even if such critical perspectives have already obtained some visibility in International Relations Theory, poststructuralist theories remain confined to the margins of IR thought. This dissertation seeks, consequently, to explore the key concept of Foucault`s thought, power, in order to reveal its assumptions as well as its implications for thinking abou global politics. By means of the analysis of the way Foucault constructs his concept of power, we arrive at the conclusion that the philosopher erases the normative borders between the concepts of power and violence. As a consequence of his conceptual indifferentiation, Foucault conceives the political phenomenon as a field of forces, as a strategic event or as a war continued by other means. This work seeks to question the normative desirability of such a conception of the political and about its capacity to provide an alternative model do realism in IR. This dissertation opposes, finally, Foucault`s vision of the political to visions that other critical perspectives, such as those inspired by the works of the Frankfurt School, offer to help us think another theoretical and practical paradigm for global politics.