The Treaty of Asunción in 1991 gave rise to the Common Market of the Southern Cone (MERCOSUR) as a promising economic integration process. Over the past 20 years, as the legal personality of MERCOSUR was reinforced, there were also important changes in its legal system. International law and international economic law played a fundamental role in the development of MERCOSUR law. The main aim of this article is to provide some insights into the current stage of MERCOSUR law, taking into account the evolution of the legal system, the dispute settlement mechanism, and the relationship with international law. In order to do so, the author examines various turning points in the case law of the arbitration tribunals constituted so far and the Permanent Review Tribunal established by the Olivos Protocol.
