In this article, basic aspects of the argumentation, the argumentation relations with the concept of logical inference and illustration argumentation on international comparative policy analysis are presented. The argumentation is understood as part of a deliberative process reasons for or against a point of view that can be defended by a confrontation of ideas. Therefore who argues: proposed refutes defeat or justify a particular worldview. For this purpose, a brief preliminary description of deductive argument systems (SDA). Degree of formalization from logic to structure the foundations of argumentation in general is introduced, then an illustration is provided based on a case widely recognized in international politics: the conditions of the public debate that led to the invasion and war against Iraq.