Matilde Pérez Herranz PhD in International Relations at the Universidad Autónoma de Madrid (2011) and PhD Extraordinary Award . Since 2007 he is Assistant Professor of International Relations at the Universitat Pompeu Fabra and a visiting professor at the Master's Degree in international Relations and African Studies Autónoma de Madrid.  Moreover, in the last few years she has been a researcher at the International Peace Research Institute ( PRIO ), Oslo , Norway (2005 to 2006) and the Maison Française in Oxford (MFO ) / Centre National de la Recherche Scientifique (CNRS ) , Oxford, United Kingdom ( 2003 to 2005). Her priority area of research is the Theory of International Relations, specifically the evolution of legitimizing the use of force and its impact on the international order. As part of it, she  has recently published working paper from the International Catalan Institute for Peace titled "The Security Council and the Legitimacy of the Use of Force : Legal , Normative and Social Aspects ."