摘要：It’s undeniable that the United States has played a role as shaper of the international system, by constructing and proposing international rules and organizations in the past century. As a hegemon, its presence can be felt in economic and security fields, as well as in politics, be on international or regional organisms. The United States has often had an important influence in some regional blocs, sometimes acting as a stepping stone, but at other times as a stumbling block to the integration. What we aim with this paper is to analyze the role of the United States in the constitution and in the definition of objectives and actions of three regional blocs: ASEAN, European Union and MERCOSUR. Our main objective is to demonstrate what kind of influence the United States has had in each process of regional integration, determining whether it acted as a sponsor or as objector, and then comparing the three cases.
